WELCOME TO ANDROID'S EXAMPLE!

The Android Source Code

Android is an open-source software stack created for a wide array of devices with different form factors. The primary purposes of Android are to create an open software platform available for carriers, OEMs, and developers to make their innovative ideas a reality and to introduce a successful, real-world product that improves the mobile experience for users.

We also wanted to make sure there was no central point of failure, where one industry player could restrict or control the innovations of any other. The result is a full, production-quality consumer product with source code open for customization and porting.
Android framework details

Figure 1. Android stack
Governance Philosophy

Android was originated by a group of companies known as the Open Handset Alliance, led by Google. Today, many companies -- both original members of the OHA and others -- have invested heavily in Android. These companies have allocated significant engineering resources to improve Android and bring Android devices to market.

The companies that have invested in Android have done so on its merits because we believe an open platform is necessary. Android is intentionally and explicitly an open-source -- as opposed to a free software -- effort; a group of organizations with shared needs has pooled resources to collaborate on a single implementation of a shared product. The Android philosophy is pragmatic, first and foremost. The objective is a shared product that each contributor can tailor and customize.

Uncontrolled customization can, of course, lead to incompatible implementations. To prevent this, the Android Open Source Project also maintains the Android Compatibility Program, which spells out what it means to be "Android compatible" and what is required of device builders to achieve that status. Anyone can (and will!) use the Android source code for any purpose, and we welcome all legitimate uses. However, in order to take part in the shared ecosystem of applications we are building around Android, device builders must participate in the Android Compatibility Program.

The Android Open Source Project is led by Google, who maintains and further develops Android. Although Android consists of multiple subprojects, this is strictly a project management technique. We view and manage Android as a single, holistic software product, not a "distribution", specification, or collection of replaceable parts. Our intent is that device builders port Android to a device; they don't implement a specification or curate a distribution.

Welcome to the Android Open Source Project!

Android is an open-source software stack for a wide range of mobile devices and a corresponding open-source project led by Google. Here you can find the information and source code you need to learn more about the Android platform. From there you can create custom variants of the Android software stack, port devices and accessories to the Android platform, and ensure your devices are compatible with the Android compatibility definition.

What's New

SELinux instructions revised The entire set of Security-Enhanced Linux instructions have been revised thanks to open source contributions.
Compatibility manual and CTS updated, CDD source made available New versions of the Compatibility Test Suite (5.0_r2) and the CTS Manual have been uploaded to the site. HTML versions of the 5.0 and 4.4 Compatibility Definition Documents (CDD) have been uploaded to AOSP for easy diffing.
Audio terminology enhanced Audio Terminology has been updated to include definitions for FIFO, lossy, transparency, and more.
Using Repo and Mac OS initializing instructions fixed The POSIXLY_CORRECT entry and Java 7 link within the Mac OS initializing instructions have been updated. And the Repo command reference has been revised to remove the replace option and point to help for the latest instructions.
Nexus 7 build tag updated The LRX22G build tag now applies to the deb and tilapia variants of Nexus 7.

Getting Started

Explore the Source Get the complete Android platform and modify and build it to suit your needs. You can also contribute to the Android Open Source Project repository to make your changes available to everyone else in the Android ecosystem.
Android framework summary Port Android to Devices Port the latest Android platform and create compelling devices that your customers want.
Build Accessories Sometimes, a device can't do it all. Tap into Android's open accessory standard and build accessories to complement the wide variety of Android-powered devices.
Get Compatible Being Android-compatible lets you offer custom features but still give users and developers a consistent and standard experience across all Android-powered devices. Android provides guidance and a test suite to verify your Android compatibility.

Source: https://source.android.com/

 

 Welcome to Android Device Manager

Android Device Manager makes it easy to locate, ring, or wipe your device from the web.

 Visit here: https://www.google.com/android/devicemanager


 

The primary source of Android apps. Also offers digital media. Requires a Google Account and the use of a client.

Visit here: https://play.google.com/store

 

 
Shop Google Play on the web. Purchase and enjoy instantly on your Android phone or tablet without the hassle of syncing.

Visit here: https://play.google.com/store


The version history of the Android mobile operating system began with the release of the Android beta in November 2007. The first commercial version, Android 1.0, was released in September 2008. Android is under ongoing development by Google and the Open Handset Alliance (OHA), and has seen a number of updates to its base operating system since its initial release.

The most recent major Android update is Android 5.0 "Lollipop", which was released on November 3, 2014. Since April 2009, Android versions have been developed under a confectionery-themed code name and released in alphabetical order, beginning with Android 1.5 "Cupcake"; the earlier versions 1.0 and 1.1 were not released under specific code names:

    Alpha (1.0)
    Beta (1.1)
    Cupcake (1.5)
    Donut (1.6)
    Eclair (2.0–2.1)
    Froyo (2.2–2.2.3)
    Gingerbread (2.3–2.3.7)
    Honeycomb (3.0–3.2.6)
    Ice Cream Sandwich (4.0–4.0.4)
    Jelly Bean (4.1–4.3.1)
    KitKat (4.4–4.4.4, 4.4W.1–4.4W.2)
    Lollipop (5.0–5.0.2)

On September 3, 2013, Google announced that one billion activated Android devices were in use worldwide. In January 2015, Android devices accounted for approximately 62% of the US smartphone and tablet market, 82.7% of the Chinese market, and 73.3% of the European market.

Pre-commercial release versions


Alpha


The development of Android started in 2003 by Android, Inc., which was purchased by Google in 2005. There were at least two internal releases of the software inside Google and the OHA before the beta version was released in November 2007. For the milestones in internal releases, names of fictional robots were chosen, with various releases code-named "Astro Boy", "Bender" and "R2-D2".

Dan Morrill created some of the first mascot logos, but the current green Android logo was designed by Irina Blok. The project manager, Ryan Gibson, conceived the confectionary-themed naming scheme that has been used for the majority of the public releases, starting with Android 1.5 "Cupcake".

Beta


The beta was released on November 5, 2007, while the software development kit (SDK) was released on November 12, 2007. The November 5 date is popularly celebrated as Android's "birthday". Public beta versions of the SDK were released in the following order:

    November 16, 2007: m3-rc22a
    December 14, 2007: m3-rc37a
    February 13, 2008: m5-rc14
    March 3, 2008: m5-rc15
    August 18, 2008: 0.9
    September 23, 2008: 1.0-r1

 

Version history by API level


The following tables show the release dates and key features of all Android operating system updates to date, listed chronologically by their official application programming interface (API) levels.


Android 1.0 (API level 1)

Android 1.0, the first commercial version of the software, was released on September 23, 2008. The first commercially available Android device was the HTC Dream. Android 1.0 incorporated the following features:

Version
Release date
Features
1.0 September 23, 2008
  • Android Market application download and updates through the Market application
  • Web browser to show, zoom and pan full HTML and XHTML web pages – multiple pages show as windows ("cards")
  • Camera support – however, this version lacked the option to change the camera's resolution, white balance, quality, etc.
  • Folders allowing the grouping of a number of application icons into a single folder icon on the Home screen
  • Access to web email servers, supporting POP3, IMAP4, and SMTP
  • Gmail synchronization with the Gmail application
  • Google Contacts synchronization with the People application
  • Google Calendar synchronization with the Calendar application
  • Google Maps with Street View to view maps and satellite imagery, as well as find local business and obtain driving directions using GPS
  • Google Sync, allowing management of over-the-air synchronization of Gmail, People, and Calendar
  • Google Search, allowing users to search the Internet and phone applications, contacts, calendar, etc.
  • Google Talk instant messaging
  • Instant messaging, text messaging, and MMS
  • Media Player, enabling management, importing, and playback of media files – however, this version lacked video and stereo Bluetooth support
  • Notifications appear in the Status bar, with options to set ringtone, LED or vibration alerts
  • Voice Dialer allows dialing and placing of phone calls without typing a name or number
  • Wallpaper allows the user to set the background image or photo behind the Home screen icons and widgets
  • YouTube video player
  • Other applications include: Alarm Clock, Calculator, Dialer (Phone), Home screen (Launcher), Pictures (Gallery), and Settings
  • Wi-Fi and Bluetooth support


Android 1.1 (API level 2)

On February 9, 2009, the Android 1.1 update was released, initially for the HTC Dream only. Android 1.1 was known as "Petit Four" internally, though this name was not used officially. The update resolved bugs, changed the Android API and added a number of features:

Version
Release date
Features
1.1 February 9, 2009
  • Details and reviews available when a user searches for businesses on Maps
  • Longer in-call screen timeout default when using the speakerphone, plus ability to show/hide dialpad
  • Ability to save attachments in messages
  • Support added for marquee in system layouts

Android 1.5 Cupcake (API level 3)

On April 27, 2009, the Android 1.5 update was released, based on Linux kernel 2.6.27. This was the first release to officially use a codename based on a dessert item ("Cupcake"), a theme which would be used for all releases henceforth. The update included several new features and UI amendments:

Version
Release date
Features
1.5 April 27, 2009
  • Support for third-party virtual keyboards with text prediction and user dictionary for custom words
  • Support for Widgets – miniature application views that can be embedded in other applications (such as the Home screen) and receive periodic updates
  • Video recording and playback in MPEG-4 and 3GP formats
  • Auto-pairing and stereo support for Bluetooth (A2DP and AVRCP profiles)
  • Copy and paste features in web browser
  • User pictures shown for Favorites in Contacts
  • Specific date/time stamp shown for events in call log, and one-touch access to a contact card from call log event
  • Animated screen transitions
  • Auto-rotation option
  • New stock boot animation
  • Ability to upload videos to YouTube
  • Ability to upload photos to Picasa

Android 1.6 Donut (API level 4)


On September 15, 2009, the Android 1.6 SDK – dubbed Donut – was released, based on Linux kernel 2.6.29. Included in the update were numerous new features:


Version
Release date
Features
1.6 September 15, 2009
  • Voice and text entry search enhanced to include bookmark history, contacts, and the web
  • Ability for developers to include their content in search results
  • Multi-lingual speech synthesis engine to allow any Android application to "speak" a string of text
  • Easier searching and ability to view app screenshots in Android Market
  • Gallery, camera and camcorder more fully integrated, with faster camera access
  • Ability for users to select multiple photos for deletion
  • Updated technology support for CDMA/EVDO, 802.1x, VPNs, and a text-to-speech engine
  • Support for WVGA screen resolutions
  • Speed improvements in searching and camera applications
  • Expanded Gesture framework and new GestureBuilder development tool

Android 2.0 Eclair (API level 5)

On October 26, 2009, the Android 2.0 SDK – codenamed Eclair – was released, based on Linux kernel 2.6.29. Changes included:



Version
Release date
Features
2.0 October 26, 2009
  • Expanded Account sync, allowing users to add multiple accounts to a device for synchronization of email and contacts
  • Microsoft Exchange email support, with combined inbox to browse email from multiple accounts in one page
  • Bluetooth 2.1 support
  • Ability to tap a Contacts photo and select to call, SMS, or email the person
  • Ability to search all saved SMS and MMS messages, with delete oldest messages in a conversation automatically deleted when a defined limit is reached
  • Numerous new camera features, including flash support, digital zoom, scene mode, white balance, color effect and macro focus
  • Improved typing speed on virtual keyboard, with smarter dictionary that learns from word usage and includes contact names as suggestions
  • Refreshed browser UI with bookmark thumbnails, double-tap zoom and support for HTML5
  • Calendar agenda view enhanced, showing attending status for each invitee, and ability to invite new guests to events
  • Optimized hardware speed and revamped UI
  • Support for more screen sizes and resolutions, with better contrast ratio
  • Improved Google Maps 3.1.2
  • MotionEvent class enhanced to track multi-touch events
  • Addition of live wallpapers, allowing the animation of home-screen background images to show movement

Android 2.0.1 Eclair (API level 6)



Version
Release date
Features
2.0.1 December 3, 2009
  • Minor API changes, bugfixes and framework behavioral changes

Android 2.2–2.2.3 Froyo (API level 8)

On May 20, 2010, the SDK for Android 2.2 (Froyo, short for frozen yogurt) was released, based on Linux kernel 2.6.32.

Version
Release date
Features
2.2 May 20, 2010
  • Speed, memory, and performance optimizations
  • Additional application speed improvements, implemented through JIT compilation
  • Integration of Chrome's V8 JavaScript engine into the Browser application
  • Support for the Android Cloud to Device Messaging (C2DM) service, enabling push notifications
  • Improved Microsoft Exchange support, including security policies, auto-discovery, GAL look-up, calendar synchronization and remote wipe
  • Improved application launcher with shortcuts to Phone and Browser applications
  • USB tethering and Wi-Fi hotspot functionality
  • Option to disable data access over mobile network.
  • Updated Market application with batch and automatic update features.
  • Quick switching between multiple keyboard languages and their dictionaries.
  • Support for Bluetooth-enabled car and desk docks
  • Support for numeric and alphanumeric passwords
  • Support for file upload fields in the Browser application
  • The browser now shows all frames of animated GIFs instead of just the first frame only
  • Support for installing applications to the expandable memory
  • Adobe Flash support
  • Support for high-PPI displays (up to 320 ppi), such as 4" 720p screens
  • Gallery allows users to view picture stacks using a zoom gesture
2.2.1 January 18, 2011
  • Bugfixes, security updates and performance improvements
2.2.2 January 22, 2011
  • Minor bugfixes, including SMS routing issues that affected the Nexus One
2.2.3 November 21, 2011
  • Two security patches

Android 2.3–2.3.2 Gingerbread (API level 9)



On December 6, 2010, the Android 2.3 (Gingerbread) SDK was released, based on Linux kernel 2.6.35. Changes included:

Version
Release date
Features
2.3 December 6, 2010
  • Updated user interface design with increased simplicity and speed
  • Support for extra-large screen sizes and resolutions (WXGA and higher)
  • Native support for SIP VoIP internet telephony
  • Faster, more intuitive text input in virtual keyboard, with improved accuracy, better suggested text and voice input mode
  • Enhanced copy/paste functionality, allowing users to select a word by press-hold, copy, and paste
  • Support for Near Field Communication (NFC), allowing the user to read an NFC tag embedded in a poster, sticker, or advertisement
  • New audio effects such as reverb, equalization, headphone virtualization, and bass boost
  • New Download Manager, giving users easy access to any file downloaded from the browser, email, or another application
  • Support for multiple cameras on the device, including a front-facing camera, if available
  • Support for WebM/VP8 video playback, and AAC audio encoding
  • Improved power management with a more active role in managing applications that are keeping the device awake for too long
  • Enhanced support for native code development
  • Switched from YAFFS to ext4 on newer devices
  • Audio, graphical, and input enhancements for game developers
  • Concurrent garbage collection for increased performance
  • Native support for more sensors (such as gyroscopes and barometers)
2.3.1 December 2010
  • Improvements and bugfixes for the Google Nexus S
2.3.2 January 2011

Android 2.3.3–2.3.7 Gingerbread (API level 10)


Version
Release date
Features
2.3.3 February 9, 2011
  • Several improvements and API fixes
2.3.4 April 28, 2011
  • Support for voice or video chat using Google Talk
  • Open Accessory Library support. Open Accessory was introduced in 3.1 (Honeycomb) but the Open Accessory Library grants 2.3.4 added support when connecting to a USB peripheral with compatible software and a compatible application on the device
  • Switched the default encryption for SSL from AES256-SHA to RC4-MD5.
2.3.5 July 25, 2011
  • Improved network performance for the Nexus S 4G, among other fixes and improvements
  • Fixed Bluetooth bug on Samsung Galaxy S
  • Improved Gmail application
  • Shadow animations for list scrolling
  • Camera software enhancements
  • Improved battery efficiency
2.3.6 September 2, 2011
  • Fixed a voice search bug
  • (The 2.3.6 update had the side-effect of impairing the Wi-Fi hotspot functionality of many Canadian Nexus S phones. Google acknowledged this problem and fixed it in late September.)
2.3.7 September 21, 2011
  • Google Wallet support for the Nexus S 4G

Android 3.0 Honeycomb (API level 11) 


On February 22, 2011, the Android 3.0 (Honeycomb) SDK – the first tablet-only Android update – was released, based on Linux kernel 2.6.36. The first device featuring this version, the Motorola Xoom tablet, was released on February 24, 2011. The update's features included:

Version
Release date
Features
3.0 February 22, 2011
  • Optimized tablet support with a new “holographic” user interface
  • Added System Bar, featuring quick access to notifications, status, and soft navigation buttons, available at the bottom of the screen
  • Added Action Bar, giving access to contextual options, navigation, widgets, or other types of content at the top of the screen
  • Simplified multitasking – tapping Recent Applications in the System Bar allows users to see snapshots of the tasks underway and quickly jump from one application to another
  • Redesigned keyboard, making typing fast, efficient and accurate on larger screen sizes
  • Simplified, more intuitive copy/paste interface
  • Multiple browser tabs replacing browser windows, plus form auto-fill and a new “incognito” mode allowing anonymous browsing
  • Quick access to camera exposure, focus, flash, zoom, front-facing camera, time-lapse, and other camera features
  • Ability to view albums and other collections in full-screen mode in Gallery, with easy access to thumbnails for other photos
  • New two-pane Contacts UI and Fast Scroll to let users easily organize and locate contacts
  • New two-pane Email UI to make viewing and organizing messages more efficient, allowing users to select one or more messages
  • Hardware acceleration
  • Support for multi-core processors
  • Ability to encrypt all user data
  • HTTPS stack improved with Server Name Indication (SNI)
  • Filesystem in Userspace (FUSE; kernel module)
  • Applications' write access to secondary storage (memory cards on devices with internal primary storage) is disabled outside of designated, app-specific directories, while full access to internal primary storage is still allowed through a separate application-level permission.

Android 3.1 Honeycomb (API level 12)


Version
Release date
Features
3.1 May 10, 2011
  • UI refinements
  • Connectivity for USB accessories (USB On-The-Go).
  • Expanded Recent Applications list
  • Resizable Home screen widgets
  • Support for external keyboards and pointing devices
  • Support for joysticks and gamepads
  • Support for FLAC audio playback
  • High-performance Wi-Fi lock, maintaining high-performance Wi-Fi connections when device screen is off
  • Support for HTTP proxy for each connected Wi-Fi access point

Android 3.2 Honeycomb (API level 13)


Most first- and second-generation Google TV-enabled devices utilize Honeycomb 3.2.

Version
Release date
Features
3.2 July 15, 2011
  • Improved hardware support, including optimizations for a wider range of tablets
  • Increased ability of applications to access files on the SD card, e.g. for synchronization
  • Compatibility display mode for applications that have not been optimized for tablet screen resolutions
  • New display support functions, giving developers more control over display appearance on different Android devices
3.2.1 September 20, 2011
  • Bugfixes and minor security, stability and Wi-Fi improvements
  • Update to Android Market with automatic updates and easier-to-read Terms and Conditions text
  • Update to Google Books
  • Improved Adobe Flash support in browser
  • Improved Chinese handwriting prediction
3.2.2 August 30, 2011
  • Bugfixes and other minor improvements for the Motorola Xoom 4G
3.2.3
  • Bugfixes and other minor improvements for the Motorola Xoom and Motorola Xoom 4G
3.2.4 December 2011
  • "Pay as You Go" support for 3G and 4G tablets
3.2.5 January 2012
  • Bugfixes and other minor improvements for the Motorola Xoom and Motorola Xoom 4G
3.2.6 February 2012
  • Fixed data connectivity issues when coming out of airplane mode on the US 4G Motorola Xoom

Android 4.0–4.0.2 Ice Cream Sandwich (API level 14)


The SDK for Android 4.0.1 (Ice Cream Sandwich), based on Linux kernel 3.0.1,  was publicly released on October 19, 2011. Google's Gabe Cohen stated that Android 4.0 was "theoretically compatible" with any Android 2.3.x device in production at that time. The source code for Android 4.0 became available on November 14, 2011. Ice Cream Sandwich was the last version to officially support Adobe Systems' Flash player. The update introduced numerous new features:

Version
Release date
Features
4.0 October 18, 2011
  • Major refinements to the "Holo" interface with new Roboto font family
  • Soft buttons from Android 3.x are now available for use on phones
  • Separation of widgets in a new tab, listed in a similar manner to applications
  • Easier-to-create folders, with a drag-and-drop style
  • Improved visual voicemail with the ability to speed up or slow down voicemail messages
  • Pinch-to-zoom functionality in the calendar
  • Integrated screenshot capture (accomplished by holding down the Power and Volume-Down buttons)
  • Improved error correction on the keyboard
  • Ability to access applications directly from lock screen
  • Improved copy and paste functionality
  • Better voice integration and continuous, real-time speech to text dictation
  • Face Unlock, a feature that allows users to unlock handsets using facial recognition software
  • Automatic syncing of browser with users' Chrome bookmarks
  • Data Usage section in settings that lets users set warnings when they approach a certain usage limit, and disable data use when the limit is exceeded
  • Ability to shut down applications from the recent apps list with a swipe.
  • Improved camera application with zero shutter lag, time lapse settings, panorama mode, and the ability to zoom while recording
  • Built-in photo editor
  • New gallery layout, organized by location and person
  • Refreshed "People" application with social network integration, status updates and hi-res images
  • Android Beam, a near-field communication feature allowing the rapid short-range exchange of web bookmarks, contact info, directions, YouTube videos and other data
  • Support for the WebP image format
  • Hardware acceleration of the UI
  • Wi-Fi Direct
  • 1080p video recording for stock Android devices
  • Android VPN Framework (AVF), and TUN (but not TAP) kernel module. Prior to 4.0, VPN software required rooted Android.
4.0.1 October 21, 2011
  • Fixed minor bugs for the Samsung Galaxy Nexus.
4.0.2 November 28, 2011
  • Fixed minor bugs on the Verizon Galaxy Nexus, the US launch of which was later delayed until December 2011
(For Canadian consumers, 4.0.2 reportedly created a bug on the Galaxy Nexus that crashed the application market when users attempted to view details of any Android application. It also inadvertently reduced the NFC capabilities of the Nexus phone.)

Android 4.0.3–4.0.4 Ice Cream Sandwich (API level 15)


Version
Release date
Features
4.0.3 December 16, 2011
  • Numerous bugfixes and optimizations
  • Improvements to graphics, databases, spell-checking and Bluetooth functionality
  • New APIs for developers, including a social stream API in the Contacts provider
  • Calendar provider enhancements
  • New camera applications enhancing video stabilization and QVGA resolution
  • Accessibility refinements such as improved content access for screen readers
4.0.4 March 29, 2012
  • Stability improvements
  • Better camera performance
  • Smoother screen rotation
  • Improved phone number recognition

Android 4.1 Jelly Bean (API level 16)


Google announced Android 4.1 (Jelly Bean) at the Google I/O conference on June 27, 2012. Based on Linux kernel 3.0.31, Jelly Bean was an incremental update with the primary aim of improving the functionality and performance of the user interface. The performance improvement involved "Project Butter", which uses touch anticipation, triple buffering, extended vsync timing and a fixed frame rate of 60 fps to create a fluid and "buttery-smooth" UI. Android 4.1 Jelly Bean was released to the Android Open Source Project on July 9, 2012, and the Nexus 7 tablet, the first device to run Jelly Bean, was released on July 13, 2012.

Version
Release date
Features
4.1 July 9, 2012
  • Smoother user interface:
    • Vsync timing across all drawing and animation done by the Android framework, including application rendering, touch events, screen composition and display refresh
    • Triple buffering in the graphics pipeline
  • Enhanced accessibility
  • Bi-directional text and other language support
  • User-installable keyboard maps
  • Expandable notifications
  • Ability to turn off notifications on an application-specific basis
  • Shortcuts and widgets can automatically be re-arranged or re-sized to allow new items to fit on home screens
  • Bluetooth data transfer for Android Beam
  • Tablets with smaller screens now use an expanded version of the interface layout and home screen used by phones.
  • Improved camera application
  • Multichannel audio
  • The Fraunhofer FDK AAC codec becomes standard in Android, adding AAC 5.1 channel encoding/decoding.
  • USB audio (for external sound DACs)
  • Audio chaining (also known as gapless playback)
  • Ability for other launchers to add widgets from the application drawer without requiring root access
4.1.1 July 11, 2012
  • Fixed a bug on the Nexus 7 regarding the inability to change screen orientation in any application
4.1.2 October 9, 2012
  • Lock/home screen rotation support for the Nexus 7
  • One-finger gestures to expand/collapse notifications
  • Bugfixes and performance enhancements

Android 4.2 Jelly Bean (API level 17)


Google was expected to announce Jelly Bean 4.2 at an event in New York City on October 29, 2012, but the event was cancelled due to Hurricane Sandy. Instead of rescheduling the live event, Google announced the new version with a press release, under the slogan "A new flavor of Jelly Bean". Jelly Bean 4.2 was based on Linux kernel 3.4.0, and debuted on Google's Nexus 4 and Nexus 10, which were released on November 13, 2012.

Version
Release date
Features
4.2 11/13/12
  • Lock screen improvements, including widget support and the ability to swipe directly to camera
  • Notification power controls ("Quick Settings")
  • "Daydream" screensavers, showing information when idle or docked
  • Multiple user accounts (tablets only)
  • Rewritten Bluetooth stack, switching from Bluez to Broadcom open source BlueDroid, allowing improved support for multiple displays and wireless display (Miracast)
  • Native right-to-left, always-on VPN and application verification. A new NFC stack was added at the same time.
  • Accessibility improvements: triple-tap to magnify the entire screen, pan and zoom with two fingers. Speech output and Gesture Mode navigation for blind users
  • New clock application with built-in world clock, stop watch and timer
  • All devices now use the same interface layout, previously adapted from phones on 4.1 for smaller tablets (with centered software buttons, the system bar at the top of the screen, and a home screen with a dock and centered application menu), regardless of screen size
  • Increased number of extended notifications and Actionable Notifications for more applications, allowing users to respond to certain notifications within the notification bar and without launching the application directly
  • SELinux
  • Premium SMS confirmation
  • Group Messaging
4.2.1 November 27, 2012
  • Fixed a bug in the People application where December was not displayed on the date selector when adding an event to a contact
  • Added Bluetooth gamepads and joysticks as supported HID (Human interface device)
4.2.2 02/11/13
  • Fixed Bluetooth audio streaming bugs
  • Long-pressing the Wi-Fi and Bluetooth icons in Quick Settings now toggles the on/off state
  • New download notifications, which now shows the percentage and estimated time remaining for active application downloads
  • New sounds for wireless charging and low battery
  • New Gallery application animation allows faster loading
  • USB debug whitelist
  • Bugfixes and performance enhancements

Android 4.3 Jelly Bean (API level 18)


Google released Jelly Bean 4.3 under the slogan "An even sweeter Jelly Bean" on July 24, 2013, during an event in San Francisco called "Breakfast with Sundar Pichai". Most Nexus devices received the update within a week, although the second-generation Nexus 7 tablet was the first device to officially ship with it. A minor bugfix update was released on August 22, 2013.

Version
Release date
Features
4.3 07/24/13
  • Bluetooth low energy support
  • Bluetooth Audio/Video Remote Control Profile (AVRCP) 1.3 support
  • OpenGL ES 3.0 support, allowing for improved game graphics
  • Restricted access mode for new user profiles
  • File system write performance improvement by running fstrim command while device is idle
  • Dial pad auto-complete in the Phone application
  • Volume for incoming calls (ring tone) and notification alerts is no longer adjustable separately
  • Improvements to Photo Sphere
  • Reworked camera UI, previously introduced on Google Play edition phones
  • Addition of "App Ops", a fine-grained application permissions control system (hidden by default)
  • 4K resolution support
  • Many security enhancements, performance enhancements, and bugfixes
  • System-level support for geofencing and Wi-Fi scanning APIs
    • Background Wi-Fi location still runs even when Wi-Fi is turned off
  • Developer logging and analyzing enhancements
  • Added support for five more languages
  • Improved digital rights management (DRM) APIs
  • Right-to-left (RTL) languages now supported
  • Clock in the status bar disappears if clock is selected as lockscreen widget
4.3.1 October 3, 2013
  • Bugfixes and small tweaks for the Nexus 7 LTE


Android 4.4 KitKat (API level 19)


Google announced Android 4.4 KitKat on September 3, 2013. Although initially under the "Key Lime Pie" ("KLP") codename, the name was changed because "very few people actually know the taste of a key lime pie." Some technology bloggers also expected the "Key Lime Pie" release to be Android 5. KitKat debuted on Google's Nexus 5 on October 31, 2013, and was optimised to run on a greater range of devices than earlier Android versions, having 512 MB of RAM as a recommended minimum; those improvements were known as "Project Svelte" internally at Google. The required minimum amount of RAM available to Android is 340 MB, and all devices with less than 512 MB of RAM must report themselves as "low RAM" devices.

Version
Release date
Features
4.4 10/31/13
  • Refreshed interface with white elements instead of blue
  • Clock no longer shows bold hours; all digits are thin. The H, M, and S markings for the stopwatch and timer have been removed, leaving just the numbers.
  • Ability for applications to trigger translucency in the navigation and status bars
  • Ability for applications to use "immersive mode" to keep the navigation and status bars hidden while maintaining user interaction
  • Action overflow menu buttons are always visible, even on devices with a "Menu" key, which was officially deprecated by Android 4.0.
  • Restriction for applications when accessing external storage, except for their own directories
  • Optimizations for performance on devices with lower specifications, including zRAM support and "low RAM" device API
  • Wireless printing capability
  • NFC host card emulation, enabling a device to replace smart cards
  • WebViews now based on Chromium engine (feature parity with Chrome for Android 30)
  • Expanded functionality for notification listener services
  • Public API for developing and managing text messaging clients
  • Storage Access Framework, an API allowing apps to retrieve files in a consistent manner. As part of the framework, a new system file picker allows users to access files from various sources (including those exposed by apps, such as online storage services).
  • New framework for UI transitions
  • Sensor batching, step detector and counter APIs
  • Settings application now makes it possible to select default text messaging and home (launcher) application
  • Audio tunneling, audio monitoring and loudness enhancer
  • Built-in screen recording feature (primarily for developers, as usage of ADB is required)
  • Native infrared blaster API
  • Expanded accessibility APIs and system-level closed captioning settings
  • Android Runtime (ART) introduced as a new experimental application runtime environment, not enabled by default, as a replacement for the Dalvik virtual machine
  • Bluetooth Message Access Profile (MAP) support
  • Disabled access to battery statistics by third-party applications
  • Settings application no longer uses a multi-pane layout on devices with larger screens
  • Wi-Fi and mobile data activity (TX/RX) indicators are moved to quick settings
  • Browser text wrap is disabled.
4.4.1 December 5, 2013
  • Improvements to auto focus, white balance and HDR+ for the Nexus 5 camera
  • Better application compatibility for the experimental Android Runtime (ART)
  • Camera application now loads Google+ Photos instead of Gallery when swiping away from the camera view
  • Miscellaneous improvements and bugfixes
4.4.2 12/09/13
  • Further security enhancements and bugfixes
  • Removal of the "App Ops" application permissions control system, introduced in Android 4.3
4.4.3 06/02/14
  • Refreshed Dialer app interface
  • Updated the Chromium based WebView to version 33 (screencasting to DevTools, HTML5 Canvas hardware acceleration performance improvements, vibration API, HTML5 form validation, HTML5 datalist)
  • Miscellaneous improvements and bugfixes
4.4.4 06/19/14
  • CVE-2014-0224 fixed, eliminating an OpenSSL man-in-the-middle vulnerability

Android 4.4 KitKat with wearable extensions (API level 20)


Version
Release date
Features
4.4W 06/25/14
  • Initial release of Android Wear platform for smartwatches: the same as Android 4.4 "KitKat", but with wearable extensions added
4.4W.1 09/06/14
  • UI updates for Google Maps navigation and alarms
4.4W.2 October 21, 2014
  • Offline music playback
  • GPS support

Android 5.0–5.0.2 Lollipop (API level 21)


Android 5.0 "Lollipop" was unveiled under the codename "Android L" on June 25, 2014, during Google I/O. It became available as official over-the-air (OTA) updates on November 12, 2014, for select devices that run distributions of Android serviced by Google, including Nexus and Google Play edition devices. Its source code was made available on November 3, 2014.

Lollipop features a redesigned user interface built around a responsive design language referred to as "material design". Other changes include improvements to the notifications, which can be accessed from the lockscreen and displayed within applications as top-of-the-screen banners. Furthermore, Google made internal changes to the platform, with the Android Runtime (ART) officially replacing Dalvik for improved application performance, and with changes intended to improve and optimize battery usage, known internally as Project Volta.

Version
Release date
Features
5 11/12/14
  • Android Runtime (ART) with ahead-of-time (AOT) compilation and improved garbage collection (GC), replacing Dalvik that uses just-in-time (JIT) compilation
  • Support for 64-bit CPUs
  • OpenGL ES 3.1 and Android Extension Pack (AEP) on supported GPU configurations
  • Recent activities screen with tasks instead of applications, up to a configured maximum of tasks per application
  • Vector drawables, which scale without losing definition
  • Support for print previews
  • Material design, bringing a restyled user interface
  • Refreshed lock screen, no longer supporting widgets
  • Refreshed notification tray and quick settings pull-down
  • Project Volta, for battery life improvements
  • Searches can be performed within the system settings for quicker access to particular settings
  • Lock screen provides shortcuts to application and notification settings
  • Guest logins and multiple user accounts are available on more devices, such as phones.
  • Audio input and output through USB devices
  • Third-party applications regain the ability to read and modify data located anywhere on external storage, such as on SD cards.
  • Pinning of an application's screen for restricted user activity.
  • Recently used applications are remembered even after restarting the device.
  • WebViews receive updates independently through Google Play for security reasons, instead of relying on system-wide vendor updates
  • Addition of 15 new languages: Basque, Bengali, Burmese, Chinese (Hong Kong), Galician, Icelandic, Kannada, Kyrgyz, Macedonian, Malayalam, Marathi, Nepali, Sinhala, Tamil and Telugu
  • Tap and Go allows users to quickly migrate to a new Android device, using NFC and Bluetooth to transfer Google Account details, configuration settings, user data and installed applications.
  • A flashlight-style application is included, working on supported devices with a camera flash.
  • User-customizable priorities for application notifications.
5.0.1 12/02/14
  • A few bugfixes, including resolving issues with video playback and password failures handling
5.0.2 12/19/14
  • Fixes a bug with TRIM support, which prevented devices from the nightly on-charger cleanups of file system allocations if the device was turned off while being charged, or if it was charged during the day
  • Changes how alarms wake the CPU, and how alarms compete for system resources

Hardware requirements


The main hardware platform for Android is the ARM architecture, with x86 and MIPS architectures also officially supported. Both 64-bit and 32-bit variants of all three architectures are supported since the release of Android 5.0; unofficial Android-x86 project had provided support for the x86 and MIPS architectures ahead of the official support. Since 2012, Android devices with Intel processors began to appear, including phones and tablets. While gaining support for 64-bit platforms, Android was first made to run on 64-bit x86 and then on ARM64.

Minimum hardware requirements have been upgraded in steps over time, with the new Android version releases. Original minimums were 32 MB of RAM (but less than 128 MB was not recommended, with first phone HTC Dream ("flagship") phone using 192 MB), 32 MB of Flash memory, and a 200 MHz ARM architecture (ARMv5) processor. As of November 2013 and Android version 4.4, builds for ARM-based devices require an ARMv7 processor (Android 5.0 also supports ARMv8-A), while recommended minimum amount of RAM is 512 MB. The required minimum amount of RAM available to Android 4.4 is 340 MB (this amount does not include memory dedicated to various hardware components such as the baseband processor), and all devices with less than 512 MB of RAM must report themselves as "low RAM" devices.

With the release of Android 4.0 in October 2011, a graphics processing unit (GPU) supporting OpenGL ES 2.0 (and ES 1.0) hardware acceleration became mandatory, regardless of whether installed applications directly use the OpenGL ES or not. Later, Android 4.3 added support for OpenGL ES 3.0; if used, support for both older versions (ES 2.0 and 1.0) is still mandatory.

In addition to running directly on x86-based hardware, Android can also be run on x86 architecture by using official Android emulator as part of the Android SDK, or by using third-party emulators such as BlueStacks or Andy.

Source: Wikipedia


Android is a mobile operating system (OS) based on the Linux kernel and currently developed by Google. With a user interface based on direct manipulation, Android is designed primarily for touchscreen mobile devices such as smartphones and tablet computers, with specialized user interfaces for televisions (Android TV), cars (Android Auto), and wrist watches (Android Wear). The OS uses touch inputs that loosely correspond to real-world actions, like swiping, tapping, pinching, and reverse pinching to manipulate on-screen objects, and a virtual keyboard. Despite being primarily designed for touchscreen input, it also has been used in game consoles, digital cameras, regular PCs (e.g. the HP Slate 21) and other electronics.

Android is the most widely used mobile OS and, as of 2013, the highest selling OS overall. Android devices sell more than Microsoft Windows, iOS, and Mac OS X devices combined, with sales in 2012, 2013 and 2014 close to the installed base of all PCs.As of July 2013 the Google Play store has had over one million Android applications ("apps") published, and over 50 billion applications downloaded. A developer survey conducted in April–May 2013 found that 71% of mobile developers develop for Android. At Google I/O 2014, the company revealed that there were over one billion active monthly Android users, up from 538 million in June 2013.

Android's source code is released by Google under open source licenses, although most Android devices ultimately ship with a combination of open source and proprietary software, including proprietary software developed and licensed by Google. Initially developed by Android, Inc., which Google backed financially and later bought in 2005, Android was unveiled in 2007 along with the founding of the Open Handset Alliance—​a consortium of hardware, software, and telecommunication companies devoted to advancing open standards for mobile devices.

Android is popular with technology companies which require a ready-made, low-cost and customizable operating system for high-tech devices. Android's open nature has encouraged a large community of developers and enthusiasts to use the open-source code as a foundation for community-driven projects, which add new features for advanced users or bring Android to devices which were officially released running other operating systems. The operating system's success has made it a target for patent litigation as part of the so-called "smartphone wars" between technology companies.

Android History

Android, Inc. was founded in Palo Alto, California in October 2003 by Andy Rubin (co-founder of Danger), Rich Miner (co-founder of Wildfire Communications, Inc.), Nick Sears (once VP at T-Mobile), and Chris White (headed design and interface development at WebTV) to develop, in Rubin's words, "smarter mobile devices that are more aware of its owner's location and preferences". The early intentions of the company were to develop an advanced operating system for digital cameras. Though, when it was realized that the market for the devices was not large enough, the company diverted its efforts toward producing a smartphone operating system that would rival Symbian and Microsoft Windows Mobile. Despite the past accomplishments of the founders and early employees, Android Inc. operated secretly, revealing only that it was working on software for mobile phones. That same year, Rubin ran out of money. Steve Perlman, a close friend of Rubin, brought him $10,000 in cash in an envelope and refused a stake in the company.

Google acquired Android Inc. on August 17, 2005; key employees of Android Inc., including Rubin, Miner, and White, stayed at the company after the acquisition. Not much was known about Android Inc. at the time, but many assumed that Google was planning to enter the mobile phone market with this move. At Google, the team led by Rubin developed a mobile device platform powered by the Linux kernel. Google marketed the platform to handset makers and carriers on the promise of providing a flexible, upgradable system. Google had lined up a series of hardware component and software partners and signaled to carriers that it was open to various degrees of cooperation on their part.

Speculation about Google's intention to enter the mobile communications market continued to build through December 2006. An earlier prototype codenamed "Sooner" had a closer resemblance to a BlackBerry phone, with no touchscreen, and a physical, QWERTY keyboard, but was later re-engineered to support a touchscreen, to compete with other announced devices such as the 2006 LG Prada and 2007 Apple iPhone. In September 2007, InformationWeek covered an Evalueserve study reporting that Google had filed several patent applications in the area of mobile telephony.

On November 5, 2007, the Open Handset Alliance, a consortium of technology companies including Google, device manufacturers such as HTC, Sony and Samsung, wireless carriers such as Sprint Nextel and T-Mobile, and chipset makers such as Qualcomm and Texas Instruments, unveiled itself, with a goal to develop open standards for mobile devices. That day, Android was unveiled as its first product, a mobile device platform built on the Linux kernel version 2.6.25. The first commercially available smartphone running Android was the HTC Dream, released on October 22, 2008.

In 2010, Google launched its Nexus series of devices – a line of smartphones and tablets running the Android operating system, and built by manufacturing partners. HTC collaborated with Google to release the first Nexus smartphone, the Nexus One. Google has since updated the series with newer devices, such as the Nexus 5 phone (made by LG) and the Nexus 7 tablet (made by Asus). Google releases the Nexus phones and tablets to act as their flagship Android devices, demonstrating Android's latest software and hardware features. On March 13, 2013 Larry Page announced in a blog post that Andy Rubin had moved from the Android division to take on new projects at Google. He was replaced by Sundar Pichai, who also continues his role as the head of Google's Chrome division, which develops Chrome OS.

Since 2008, Android has seen numerous updates which have incrementally improved the operating system, adding new features and fixing bugs in previous releases. Each major release is named in alphabetical order after a dessert or sugary treat; for example, version 1.5 Cupcake was followed by 1.6 Donut. Version 4.4.4 KitKat appeared as a security-only update; it was released on June 19, 2014, shortly after 4.4.3 was released. As of November 2014, the newest version of the Android operating system, Android 5.0 "Lollipop", is available for selected devices.

From 2010 to 2013, Hugo Barra served as product spokesperson for the Android team, representing Android at both press conferences and Google I/O, Google’s annual developer-focused conference. Barra’s product involvement included the entire Android ecosystem of software and hardware, including Honeycomb, Ice Cream Sandwich, Jelly Bean and KitKat operating system launches, the Nexus 4 and Nexus 5 smartphones, the Nexus 7 and Nexus 10 tablets, and other related products such as Google Now and Google Voice Search, Google’s speech recognition product comparable to Apple’s Siri. In 2013, Barra left the Android team for Chinese smartphone maker Xiaomi.

Android Features


Interface

 

Android's default user interface is based on direct manipulation, using touch inputs, that loosely correspond to real-world actions, like swiping, tapping, pinching, and reverse pinching to manipulate on-screen objects, and a virtual keyboard. The response to user input is designed to be immediate and provides a fluid touch interface, often using the vibration capabilities of the device to provide haptic feedback to the user. Internal hardware such as accelerometers, gyroscopes and proximity sensors are used by some applications to respond to additional user actions, for example adjusting the screen from portrait to landscape depending on how the device is oriented, or allowing the user to steer a vehicle in a racing game by rotating the device, simulating control of a steering wheel.

Android devices boot to the homescreen, the primary navigation and information point on the device, which is similar to the desktop found on PCs. Android homescreens are typically made up of app icons and widgets; app icons launch the associated app, whereas widgets display live, auto-updating content such as the weather forecast, the user's email inbox, or a news ticker directly on the homescreen. A homescreen may be made up of several pages that the user can swipe back and forth between, though Android's homescreen interface is heavily customisable, allowing the user to adjust the look and feel of the device to their tastes. Third-party apps available on Google Play and other app stores can extensively re-theme the homescreen, and even mimic the look of other operating systems, such as Windows Phone. Most manufacturers, and some wireless carriers, customise the look and feel of their Android devices to differentiate themselves from their competitors.

Present along the top of the screen is a status bar, showing information about the device and its connectivity. This status bar can be "pulled" down to reveal a notification screen where apps display important information or updates, such as a newly received email or SMS text, in a way that does not immediately interrupt or inconvenience the user. Notifications are persistent until read (by tapping, which opens the relevant app) or dismissed by sliding it off the screen. Beginning on Android 4.1, "expanded notifications" can display expanded details or additional functionality; for instance, a music player can display playback controls, and a "missed call" notification provides buttons for calling back or sending the caller an SMS message.

Android provides the ability to run applications which change the default launcher and hence the appearance and externally visible behaviour of Android. These appearance changes include a multi-page dock or no dock, and many more changes to fundamental features of the user interface.

Applications


Applications ("apps"), that extend the functionality of devices, are written primarily in the Java programming language (without the usual "write once, run anywhere" claim of the Java platform) using the Android software development kit (SDK). The SDK includes a comprehensive set of development tools, including a debugger, software libraries, a handset emulator based on QEMU, documentation, sample code, and tutorials. The officially supported integrated development environment (IDE) is Eclipse using the Android Development Tools (ADT) plugin. Other development tools are available, including a Native Development Kit for applications or extensions in C or C++, Google App Inventor, a visual environment for novice programmers, and various cross platform mobile web applications frameworks. In January 2014, Google unveiled an Apache Cordova–based framework for porting Chrome HTML 5 applications to Android, wrapped in a native application shell.

Android has a growing selection of third-party applications, which can be acquired by users by downloading and installing the application's APK file, or by downloading them using an application store program that allows users to install, update, and remove applications from their devices. Google Play Store is the primary application store installed on Android devices that comply with Google's compatibility requirements and license the Google Mobile Services software. Google Play Store allows users to browse, download and update applications published by Google and third-party developers; As of July 2013, there are more than one million applications available for Android in Play Store. As of May 2013, 48 billion applications have been installed from Google Play Store and in July 2013, 50 billion applications were installed. Some carriers offer direct carrier billing for Google Play application purchases, where the cost of the application is added to the user's monthly bill.

Due to the open nature of Android, a number of third-party application marketplace also exist for Android, either to provide a substitute for devices that are not allowed to ship with Google Play Store, provide applications that cannot be offered on Google Play Store due to policy violations, or for other reasons. Examples of these third-party stores have included the Amazon Appstore, GetJar, and SlideMe. F-Droid, another alternative marketplace, seeks to only provide applications that are distributed under free and open source licenses.

Memory management


Since Android devices are usually battery-powered, Android is designed to manage memory (RAM) to keep power consumption at a minimum, in contrast to desktop operating systems which generally assume they are connected to unlimited mains electricity. When an Android application is no longer in use, the system will automatically suspend it in memory; while the application is still technically "open", suspended applications consume no resources (for example, battery power or processing power) and sit idly in the background until needed again. This brings a dual benefit by increasing the general responsiveness of Android devices, since applications do not need to be closed and reopened from scratch each time, and by ensuring that background applications do not consume power needlessly.

Android manages the applications stored in memory automatically: when memory is low, the system will begin killing applications and processes that have been inactive for a while, in reverse order since they were last used (oldest first). This process is designed to be invisible to the user, so that users do not need to manage memory or the killing of applications themselves. As of 2011, third-party task killers were reported by Lifehacker as doing more harm than good.

Hardware


The main hardware platform for Android is the ARM architecture (ARMv7 or later, Android 5.0 also supports ARMv8-A), with x86 and MIPS architectures also officially supported. Both 64-bit and 32-bit variants of all three architectures are supported since the release of Android 5.0. Since 2012, Android devices with Intel processors began to appear, including phones and tablets.

As of November 2013, Android 4.4 recommends at least 512 MB of RAM, while for "low RAM" devices 340 MB is the required minimum amount that does not include memory dedicated to various hardware components such as the baseband processor. Android 4.4 requires a 32-bit ARMv7, MIPS or x86 architecture processor (latter two through unofficial ports), together with an OpenGL ES 2.0 compatible graphics processing unit (GPU). Android supports OpenGL ES 1.1, 2.0, 3.0 and 3.1. Some applications may explicitly require a certain version of the OpenGL ES, and suitable GPU hardware is required to run such applications.

Android devices incorporate many optional hardware components, including still or video cameras, GPS, orientation sensors, dedicated gaming controls, accelerometers, gyroscopes, barometers, magnetometers, proximity sensors, pressure sensors, thermometers, and touchscreens. Some hardware components are not required, but became standard in certain classes of devices, such as smartphones, and additional requirements apply if they are present. Some other hardware was initially required, but those requirements have been relaxed or eliminated altogether. For example, as Android was developed initially as a phone OS, hardware such as microphones were required, while over time the phone function became optional. Android used to require an autofocus camera, which was relaxed to a fixed-focus camera if it is even present at all, since the camera was dropped as a requirement entirely when Android started to be used on set-top boxes.

In addition to running on smartphones and tablets, several vendors run Android natively on regular PC hardware with a keyboard and mouse. In addition to their availability on commercially available hardware, similar PC hardware–friendly versions of Android are freely available from the Android-x86 project, including customized Android 4.4. Using the Android emulator that is part of the Android SDK, or by using BlueStacks or Andy, Android can also run non-natively on x86. Chinese companies are building a PC and mobile operating system, based on Android, to "compete directly with Microsoft Windows and Google Android". The Chinese Academy of Engineering noted that "more than a dozen" companies were customising Android following a Chinese ban on the use of Windows 8 on government PCs.

Development


Android is developed in private by Google until the latest changes and updates are ready to be released, at which point the source code is made available publicly. This source code will only run without modification on select devices, usually the Nexus series of devices. The source code is, in turn, adapted by OEMs to run on their hardware. Android's source code does not contain the often proprietary device drivers that are needed for certain hardware components.

The green Android logo was designed for Google in 2007 by graphic designer Irina Blok. The design team was tasked with a project to create a universally identifiable icon with the specific inclusion of a robot in the final design. After numerous design developments based on science-fiction and space movies, the team eventually sought inspiration from the human symbol on restroom doors and modified the figure into a robot shape. As Android is open-sourced, it was agreed that the logo should be likewise, and since its launch the green logo has been reinterpreted into countless variations on the original design.

Update schedule


Google provides major incremental upgrades to Android every six to nine months, with confectionary-themed names, which most devices are capable of receiving over the air. The latest major release is Android 5.0 "Lollipop".

Compared to its chief rival mobile operating system, namely iOS, Android updates are typically slow to reach actual devices. For devices not under the Nexus brand, updates often arrive months from the time the given version is officially released. This is partly due to the extensive variation in hardware of Android devices, to which each upgrade must be specifically tailored, as the official Google source code only runs on their flagship Nexus devices. Porting Android to specific hardware is a time- and resource-consuming process for device manufacturers, who prioritize their newest devices and often leave older ones behind. Hence, older smartphones are frequently not updated if the manufacturer decides it is not worth their time, regardless of whether the phone is capable of running the update. This problem is compounded when manufacturers customize Android with their own interface and apps, which must be reapplied to each new release. Additional delays can be introduced by wireless carriers who, after receiving updates from manufacturers, further customize and brand Android to their needs and conduct extensive testing on their networks before sending the upgrade out to users.

The lack of after-sale support from manufacturers and carriers has been widely criticized by consumer groups and the technology media. Some commentators have noted that the industry has a financial incentive not to upgrade their devices, as the lack of updates for existing devices fuels the purchase of newer ones, an attitude described as "insulting". The Guardian has complained that the method of distribution for updates is complicated only because manufacturers and carriers have designed it that way. In 2011, Google partnered with a number of industry players to announce an "Android Update Alliance", pledging to deliver timely updates for every device for 18 months after its release; however, there has not been another official word about that alliance.

In 2012, Google began decoupling certain aspects of the operating system (particularly core applications) so they could be updated through Google Play Store, independently of Android itself. One of these components, Google Play Services, is a closed-source system-level process providing APIs for Google services, installed automatically on nearly all devices running Android version 2.2 and higher. With these changes, Google can add new operating system functionality through Play Services and application updates without having to distribute an upgrade to the operating system itself. As a result, Android 4.2 and 4.3 contained relatively fewer user-facing changes, focusing more on minor changes and platform improvements.

Linux kernel


Android's kernel is based on one of the Linux kernel's long-term support (LTS) branches. Since April 2014, Android devices mainly use versions 3.4 or 3.10 of the Linux kernel. The specific kernel version depends on the actual Android device and its hardware platform;  Android has used various kernel versions since the version 2.6.25 that was used in Android 1.0.

Android's variant of the Linux kernel has further architectural changes that are implemented by Google outside the typical Linux kernel development cycle, such as the inclusion of components like Binder, ashmem, pmem, logger, wakelocks, and different out-of-memory (OOM) handling. Certain features that Google contributed back to the Linux kernel, notably a power management feature called "wakelocks", were rejected by mainline kernel developers partly because they felt that Google did not show any intent to maintain its own code. Google announced in April 2010 that they would hire two employees to work with the Linux kernel community, but Greg Kroah-Hartman, the current Linux kernel maintainer for the stable branch, said in December 2010 that he was concerned that Google was no longer trying to get their code changes included in mainstream Linux. Some Google Android developers hinted that "the Android team was getting fed up with the process," because they were a small team and had more urgent work to do on Android.

In August 2011, Linus Torvalds said that "eventually Android and Linux would come back to a common kernel, but it will probably not be for four to five years". In December 2011, Greg Kroah-Hartman announced the start of Android Mainlining Project, which aims to put some Android drivers, patches and features back into the Linux kernel, starting in Linux 3.3. Linux included the autosleep and wakelocks capabilities in the 3.5 kernel, after many previous attempts at merger. The interfaces are the same but the upstream Linux implementation allows for two different suspend modes: to memory (the traditional suspend that Android uses), and to disk (hibernate, as it is known on the desktop). Google maintains a public code repository that contains their experimental work to re-base Android off the latest stable Linux versions.

The flash storage on Android devices is split into several partitions, such as /system for the operating system itself, and /data for user data and application installations. In contrast to desktop Linux distributions, Android device owners are not given root access to the operating system and sensitive partitions such as /system are read-only. However, root access can be obtained by exploiting security flaws in Android, which is used frequently by the open-source community to enhance the capabilities of their devices, but also by malicious parties to install viruses and malware.

Android is a Linux distribution according to the Linux Foundation, Google's open-source chief Chris DiBona,  and several journalists. Others, such as Google engineer Patrick Brady, say that Android is not Linux in the traditional Unix-like Linux distribution sense; Android does not include the GNU C Library and some of other components typically found in Linux distributions.

Software stack


On top of the Linux kernel, there are the middleware, libraries and APIs written in C, and application software running on an application framework which includes Java-compatible libraries based on Apache Harmony. Development of the Linux kernel continues independently of other Android's source code bases.

Until version 5.0, Android used Dalvik as a process virtual machine with just-in-time (JIT) compilation to run Dalvik "dex-code" (Dalvik Executable), which is usually translated from the Java bytecode. Following the JIT principle, Dalvik performs the compilation each time an application is launched. Android 4.4 introduced Android Runtime (ART) as a new runtime environment, which uses ahead-of-time (AOT) compilation to compile the bytecode upon the installation of an application. In Android 4.4, ART was an experimental feature and not enabled by default; it became the only runtime option in the next major version of Android, 5.0.

Android's standard C library, Bionic, was developed by Google specifically for Android, as a derivation of the BSD's standard C library code. Bionic itself has been designed with several major features specific to the Linux kernel. The main benefits of using Bionic instead of the GNU C Library (glibc) or uClibc are its smaller runtime footprint, and optimization for low-frequency CPUs. At the same time, Bionic is licensed under the terms of BSD licence, which Google finds more suitable for the Android's overall licensing model.

Aiming for a different licensing model, toward the end of 2012 Google switched the Bluetooth stack in Android from the GPL-licensed BlueZ to the Apache-licensed BlueDroid.

Android does not have a native X Window System by default, nor does it support the full set of standard GNU libraries. This made it difficult to port existing Linux applications or libraries to Android, until version r5 of the Android Native Development Kit brought support for applications written completely in C or C++. Libraries written in C may also be used in applications by injection of a small shim and usage of the JNI.

Open-source community


Android has an active community of developers and enthusiasts who use the Android Open Source Project (AOSP) source code to develop and distribute their own modified versions of the operating system. These community-developed releases often bring new features and updates to devices faster than through the official manufacturer/carrier channels, albeit without as extensive testing or quality assurance; provide continued support for older devices that no longer receive official updates; or bring Android to devices that were officially released running other operating systems, such as the HP TouchPad. Community releases often come pre-rooted and contain modifications unsuitable for non-technical users, such as the ability to overclock or over/undervolt the device's processor. CyanogenMod is the most widely used community firmware, and acts as a foundation for numerous others.

Historically, device manufacturers and mobile carriers have typically been unsupportive of third-party firmware development. Manufacturers express concern about improper functioning of devices running unofficial software and the support costs resulting from this. Moreover, modified firmwares such as CyanogenMod sometimes offer features, such as tethering, for which carriers would otherwise charge a premium. As a result, technical obstacles including locked bootloaders and restricted access to root permissions are common in many devices. However, as community-developed software has grown more popular, and following a statement by the Librarian of Congress in the United States that permits the "jailbreaking" of mobile devices, manufacturers and carriers have softened their position regarding third party development, with some, including HTC, Motorola, Samsung and Sony, providing support and encouraging development. As a result of this, over time the need to circumvent hardware restrictions to install unofficial firmware has lessened as an increasing number of devices are shipped with unlocked or unlockable bootloaders, similar to Nexus series of phones, although usually requiring that users waive their devices' warranties to do so. However, despite manufacturer acceptance, some carriers in the US still require that phones are locked down, frustrating developers and customers.

Security and privacy


Android applications run in a sandbox, an isolated area of the system that does not have access to the rest of the system's resources, unless access permissions are explicitly granted by the user when the application is installed. Before installing an application, Play Store displays all required permissions: a game may need to enable vibration or save data to an SD card, for example, but should not need to read SMS messages or access the phonebook. After reviewing these permissions, the user can choose to accept or refuse them, installing the application only if they accept. The sandboxing and permissions system lessens the impact of vulnerabilities and bugs in applications, but developer confusion and limited documentation has resulted in applications routinely requesting unnecessary permissions, reducing its effectiveness. Google has now pushed an update to Android Verify Apps feature, which will now run in background to detect malicious processes and crack them down.

The "App Ops" privacy and application permissions control system, used for internal development and testing by Google, was introduced in Google's Android 4.3 release for the Nexus devices. Initially hidden, the feature was discovered publicly; it allowed users to install a management application and approve or deny permission requests individually for each of the applications installed on a device. Access to the App Ops was later restricted by Google starting with Android 4.4.2 with an explanation that the feature was accidentally enabled and not intended for end-users; for such a decision, Google received criticism from the Electronic Frontier Foundation. Individual application permissions management, through the App Ops or third-party tools, is currently only possible with root access to the device.

Research from security company Trend Micro lists premium service abuse as the most common type of Android malware, where text messages are sent from infected phones to premium-rate telephone numbers without the consent or even knowledge of the user. Other malware displays unwanted and intrusive adverts on the device, or sends personal information to unauthorised third parties. Security threats on Android are reportedly growing exponentially; however, Google engineers have argued that the malware and virus threat on Android is being exaggerated by security companies for commercial reasons, and have accused the security industry of playing on fears to sell virus protection software to users. Google maintains that dangerous malware is actually extremely rare, and a survey conducted by F-Secure showed that only 0.5% of Android malware reported had come from the Google Play store.

Google currently uses Google Bouncer malware scanner to watch over and scan the Google Play store apps. It is intended to flag up suspicious apps and warn users of any potential threat with an application before they download it. Android version 4.2 Jelly Bean was released in 2012 with enhanced security features, including a malware scanner built into the system, which works in combination with Google Play but can scan apps installed from third party sources as well, and an alert system which notifies the user when an app tries to send a premium-rate text message, blocking the message unless the user explicitly authorises it. Several security firms, such as Lookout Mobile Security, AVG Technologies, and McAfee, have released antivirus software for Android devices. This software is ineffective as sandboxing also applies to such applications, limiting their ability to scan the deeper system for threats.

Android smartphones have the ability to report the location of Wi-Fi access points, encountered as phone users move around, to build databases containing the physical locations of hundreds of millions of such access points. These databases form electronic maps to locate smartphones, allowing them to run apps like Foursquare, Google Latitude, Facebook Places, and to deliver location-based ads. Third party monitoring software such as TaintDroid, an academic research-funded project, can, in some cases, detect when personal information is being sent from applications to remote servers. In August 2013, Google released Android Device Manager (ADM), a component that allows users to remotely track, locate, and wipe their Android device through a web interface. In December 2013, Google released ADM as an Android application on the Google Play store, where it is available to devices running Android version 2.2 and higher.

The open-source nature of Android allows security contractors to take existing devices and adapt them for highly secure uses. For example Samsung has worked with General Dynamics through their Open Kernel Labs acquisition to rebuild Jelly Bean on top of their hardened microvisor for the "Knox" project.

As part of the broader 2013 mass surveillance disclosures it was revealed in September 2013 that the American and British intelligence agencies, the National Security Agency (NSA) and Government Communications Headquarters (GCHQ) respectively, have access to the user data on iPhone, BlackBerry, and Android devices. They are reportedly able to read almost all smartphone information, including SMS, location, emails, and notes. Further reports in January 2014 revealed the intelligence agencies capabilities to intercept the personal information transmitted across the internet by social networks and other popular apps such as Angry Birds, which collect personal information of their users for advertising and other commercial reasons. GCHQ has, according to The Guardian, a wiki-style guide of different apps and advertising networks, and the different data that can be siphoned from each. Later that week, the Finnish Angry Birds developer Rovio announced that it was reconsidering its relationships with its advertising platforms in the light of these revelations, and called upon the wider industry to do the same.

The documents revealed a further effort by the intelligence agencies to intercept Google Maps searches and queries submitted from Android and other smartphones to collect location information in bulk. The NSA and GCHQ insist their activities are in compliance with all relevant domestic and international laws, although the Guardian stated "the latest disclosures could also add to mounting public concern about how the technology sector collects and uses information, especially for those outside the US, who enjoy fewer privacy protections than Americans."

Licensing


The source code for Android is open source; it is developed in private by Google, with the source code released publicly when a new version of Android is released. Google publishes most of the code (including network and telephony stacks) under the non-copyleft Apache License version 2.0. which allows modification and redistribution. The license does not grant rights to the "Android" trademark, so device manufacturers and wireless carriers have to license it from Google under individual contracts. Associated Linux kernel changes are released under the copyleft GNU General Public License version 2, developed by the Open Handset Alliance, with the source code publicly available at all times. Typically, Google collaborates with a hardware manufacturer to produce a flagship device (part of the Nexus series) featuring the new version of Android, then makes the source code available after that device has been released. The only Android release which was not immediately made available as source code was the tablet-only 3.0 Honeycomb release. The reason, according to Andy Rubin in an official Android blog post, was because Honeycomb was rushed for production of the Motorola Xoom, and they did not want third parties creating a "really bad user experience" by attempting to put onto smartphones a version of Android intended for tablets.

While all of Android itself is open source software, most Android devices ship with a large amount of proprietary software, such as Google Mobile Services, which includes apps such as Google Play Store, Google Search, and Google Play Services—a software layer which provides APIs that integrate with Google-provided services, among others. These apps must be licensed from Google by device makers, and can only be shipped on devices which meet its compatibility guidelines and other requirements. Custom, certified distributions of Android produced by manufacturers (such as TouchWiz and HTC Sense) may also replace certain stock Android apps with their own proprietary variants and add additional software not included in the stock Android operating system. There may also be "binary blob" drivers required for certain hardware components in the device.

Several stock apps in Android's open source code used by previous versions (such as Search, Music, and Calendar) have also been effectively deprecated by Google, with development having shifted to newer but proprietary versions distributed and updated through Play Store, such as Google Search and Google Play Music. While these older apps remain in Android's source code, they have no longer received any major updates. Additionally, proprietary variants of the stock Camera and Gallery apps also include certain functions (such as Photosphere panoramas and Google+ album integration) that are excluded from open source versions (however, they have yet to be completely abandoned). Similarly, the Nexus 5 uses a non-free variation of Android 4.4's home screen that is embedded directly within the Google Search app, adding voice-activated search and the ability to access Google Now as a page on the home screen itself. Although an update for Google Search app containing the relevant components was released through Google Play for all Android devices, the new home screen required an additional stub application to function, and was not provided in Android 4.4 updates for any other devices (which still used the existing home screen from Android version 4.3). The stub application was officially released on Play Store as Google Now Launcher in February 2014, initially for Nexus and Google Play Edition devices with Android version 4.4.

Richard Stallman and the Free Software Foundation have been critical of Android and have recommended the usage of alternatives such as Replicant, because drivers and firmware vital for the proper functioning of Android devices are usually proprietary, and because Google Play can forcibly install or deinstall apps and invites non-free software.

Leverage over manufacturers


Google Mobile Services software, along with Android trademarks, can only be licensed by hardware manufacturers for devices that meet Google's compatibility standards contained within Android Compatibility Definition Document. Thus, forks of Android that make major changes to the operating system itself do not include any of Google's non-free components, stay incompatible with applications that require them, and must ship with an alternative software marketplace in lieu of Google Play Store. Examples of such Android forks are the Amazon's Fire OS (which is used on the Kindle Fire line of tablets, and oriented toward Amazon services), the Nokia X Software Platform (a fork used by the Nokia X family, oriented primarily toward Nokia and Microsoft services), and other forks that exclude Google apps due to the general unavailability of Google service in that country and licensing fees (such as in China). In 2014, Google also began to require that all Android devices which license the Google Mobile Services software display a prominent "Powered by Android" logo on their boot screens.

Members of the Open Handset Alliance, which include the majority of Android OEMs, are also contractually forbidden from producing Android devices based on forks of the OS; in 2012, Acer Inc. was forced by Google to halt production on a device powered by Alibaba Group's Aliyun OS with threats of removal from the OHA, as Google deemed the platform to be an incompatible version of Android. Alibaba Group defended the allegations, arguing that the OS was a distinct platform from Android (primarily using HTML5 apps), but incorporated portions of Android's platform to allow backwards compatibility with third-party Android software. Indeed, the devices did ship with an application store which offered Android apps; however, the majority of them were pirated.

Reception


Android received a lukewarm reaction when it was unveiled in 2007. Although analysts were impressed with the respected technology companies that had partnered with Google to form the Open Handset Alliance, it was unclear whether mobile phone manufacturers would be willing to replace their existing operating systems with Android. The idea of an open-source, Linux-based development platform sparked interest, but there were additional worries about Android facing strong competition from established players in the smartphone market, such as Nokia and Microsoft, and rival Linux mobile operating systems that were in development. These established players were skeptical: Nokia was quoted as saying "we don't see this as a threat," and a member of Microsoft's Windows Mobile team stated "I don't understand the impact that they are going to have."

Since then Android has grown to become the most widely used smartphone operating system and "one of the fastest mobile experiences available." Reviewers have highlighted the open-source nature of the operating system as one of its defining strengths, allowing companies such as Nokia (Nokia X family), Amazon (Kindle Fire), Barnes & Noble (Nook), Ouya, Baidu and others to fork the software and release hardware running their own customised version of Android. As a result, it has been described by technology website Ars Technica as "practically the default operating system for launching new hardware" for companies without their own mobile platforms. This openness and flexibility is also present at the level of the end user: Android allows extensive customisation of devices by their owners and apps are freely available from non-Google app stores and third party websites. These have been cited as among the main advantages of Android phones over others.

Despite Android's popularity, including an activation rate three times that of iOS, there have been reports that Google has not been able to leverage their other products and web services successfully to turn Android into the money maker that analysts had expected. The Verge suggested that Google is losing control of Android due to the extensive customization and proliferation of non-Google apps and services—Amazon's Kindle Fire line uses Fire OS, a heavily modified fork of Android which does not include or support any of Google's proprietary components, and requires that users obtain software from its competing Amazon Appstore instead of Play Store. In 2014, in an effort to improve prominence of the Android brand, Google began to require that devices featuring its proprietary components display an Android logo on the boot screen.

Android has suffered from "fragmentation", a situation where the variety of Android devices, in terms of both hardware variations and differences in the software running on them, makes the task of developing applications that work consistently across the ecosystem harder than rival platforms such as iOS where hardware and software varies less. For example, according to data from OpenSignal in July 2013, there were 11,868 models of Android device, numerous different screen sizes and eight Android OS versions simultaneously in use, while the large majority of iOS users have upgraded to the latest iteration of that OS. Critics such as Apple Insider have asserted that fragmentation via hardware and software pushed Android's growth through large volumes of low end, budget-priced devices running older versions of Android. They maintain this forces Android developers to write for the "lowest common denominator" to reach as many users as possible, who have too little incentive to make use of the latest hardware or software features only available on a smaller percentage of devices. However, OpenSignal, who develops both Android and iOS apps, concluded that although fragmentation can make development trickier, Android's wider global reach also increases the potential reward.

Market share


Research company Canalys estimated in the second quarter of 2009 that Android had a 2.8% share of worldwide smartphone shipments. By the fourth quarter of 2010 this had grown to 33% of the market, becoming the top-selling smartphone platform,  overtaking Symbian. By the third quarter of 2011 Gartner estimated that more than half (52.5%) of the smartphone sales belonged to Android. By the third quarter of 2012 Android had a 75% share of the global smartphone market according to the research firm IDC.

In July 2011, Google said that 550,000 new Android devices were being activated every day, up from 400,000 per day in May, and more than 100 million devices had been activated with 4.4% growth per week. In September 2012, 500 million devices had been activated with 1.3 million activations per day. In May 2013, at Google I/O, Sundar Pichai announced that 900 million Android devices had been activated.

Android market share varies by location. In July 2012, "mobile subscribers aged 13+" in the United States using Android were up to 52%, and rose to 90% in China. During the third quarter of 2012, Android's worldwide smartphone shipment market share was 75%, with 750 million devices activated in total. In April 2013 Android had 1.5 million activations per day. As of May 2013, 48 billion applications ("apps") have been installed from the Google Play store, and by September 2013, one billion Android devices have been activated.

Android has the largest installed base of any mobile operating system and, as of 2013, devices running it also sell more than Windows, iOS and Mac OS X devices combined. In the third quarter of 2013, Android's share of the global smartphone shipment market was 81.3%, the highest ever, and the Android share—​led by Samsung products—​was 81.3%; During this time period over 261 million smartphones were sold globally, with around 211 million of those running Android.


As of July 2013, the Google Play store has had over one million Android applications published, and over 50 billion applications downloaded. A developer survey conducted in April–May 2013 found that Android is used by 71% of mobile developers. The operating system's success has made it a target for patent litigation as part of the so-called "smartphone wars" between technology companies.

Android devices account for more than half of smartphone sales in most markets, including the US, while "Only in Japan was Apple on top" (September–November 2013 numbers). At the end of 2013, over 1.5 billion Android smartphones have been sold in the four years since 2010, making Android the most sold phone and tablet OS. Three billion Android smartphones are estimated to be sold by the end of 2014 (including previous years). According to Gartner research company, Android-based devices outsold all contenders, every year since 2012. In 2013, it outsold Windows 2.8:1 or by 573 million.

Since July 2014, Android is the most popular mobile operating system when it comes to use for web browsing, according to NetApplications. In India and other countries, Android is the most popular operating system overall (not just counting the "mobile" ones) for web browsing usage. According to StatCounter, "mobile usage has already overtaken desktop in several countries including India, South Africa and Saudi Arabia", with several countries in Africa having done so already, including Ethiopia and Kenya in which mobile usage is at 72.23%.

While Android phones in the west commonly include Google's proprietary add-ons (such as Google Play) to the otherwise open source operating system, increasingly this is not done in emerging markets; "ABI Research claims that 65 million devices shipped globally with open-source Android in the second quarter of 2014, up from 54 million in the first quarter"; depending on country, percent of phones estimated to be based only on Android's source code (AOSP), forgoing the Android trademark: Thailand (44%), Philippines (38%), Indonesia (31%), India (21%), Malaysia (24%), Mexico (18%), Brazil (9%).

According to Gartner, "Android surpassed a billion shipments of devices in 2014, and will continue to grow at a double-digit pace in 2015, with a 26 percent increase year over year." This makes it the first time that any general-purpose operating system has reached more than one billion end users within a year: by reaching close to 1.16 billion end users in 2014, Android shipped over four times more than iOS and OS X combined, and over three times more than Microsoft Windows. Gartner expects the whole mobile phone market to "reach two billion units in 2016", including Android.

Tablets


Despite its success on smartphones, initially Android tablet adoption was slow. One of the main causes was the chicken or the egg situation where consumers were hesitant to buy an Android tablet due to a lack of high quality tablet applications, but developers were hesitant to spend time and resources developing tablet applications until there was a significant market for them. The content and app "ecosystem" proved more important than hardware specs as the selling point for tablets. Due to the lack of Android tablet-specific applications in 2011, early Android tablets had to make do with existing smartphone applications that were ill-suited to larger screen sizes, whereas the dominance of Apple's iPad was reinforced by the large number of tablet-specific iOS applications.

Despite app support in its infancy, a considerable number of Android tablets (alongside those using other operating systems, such as the HP TouchPad and BlackBerry PlayBook) were rushed out to market in an attempt to capitalize on the success of the iPad. InfoWorld has suggested that some Android manufacturers initially treated their first tablets as a "Frankenphone business", a short-term low-investment opportunity by placing a smartphone-optimized Android OS (before Android 3.0 Honeycomb for tablets was available) on a device while neglecting user interface. This approach, such as with the Dell Streak, failed to gain market traction with consumers as well as damaging the early reputation of Android tablets. Furthermore, several Android tablets such as the Motorola Xoom were priced the same or higher than the iPad, which hurt sales. An exception was the Amazon Kindle Fire, which relied upon lower pricing as well as access to Amazon's ecosystem of applications and content.

This began to change in 2012 with the release of the affordable Nexus 7 and a push by Google for developers to write better tablet applications.
According to International Data Corporation, shipments of Android-powered tablets surpassed iPads in Q3 2012.

As of the end of 2013, over 191.6 million Android tablets had sold in three years since 2011. This made Android tablets the most-sold type of tablet in 2013, surpassing iPads in the second quarter of 2013.

Platform usage


Charts in this section provide breakdowns of Android versions, based on the devices accessing the Play Store in a seven-day period ending on February 2, 2015. Therefore, these statistics exclude Android forks that do not access Google Play, such as Amazon's Fire tablets.
Version Code name Release date API level Distribution
2.2 Froyo May 20, 2010 8 0.4%
2.3.3–2.3.7 Gingerbread February 9, 2011 10 7.4%
4.0.3–4.0.4 Ice Cream Sandwich December 16, 2011 15 6.4%
4.1.x Jelly BeanJuly 9, 2012 16 18.4%
4.2.x Jelly BeanNovember 13, 2012 17 19.8%
4.3 Jelly Bean July 24, 2013 18 6.3%
4.4 KitKat October 31, 2013 19 39.7%
5.0 Lollipop November 3, 2014 21 1.6%

Application piracy

In general, paid Android applications can easily be pirated. In a May 2012 interview with Eurogamer, the developers of Football Manager stated that the ratio of pirated players vs legitimate players was 9:1 for their game Football Manager Handheld. However, not every developer agreed that piracy rates were an issue; for example, in July 2012 the developers of the game Wind-up Knight said that piracy levels of their game were only 12%, and most of the piracy came from China, where people cannot purchase apps from Google Play.

In 2010, Google released a tool for validating authorized purchases for use within apps, but developers complained that this was insufficient and trivial to crack. Google responded that the tool, especially its initial release, was intended as a sample framework for developers to modify and build upon depending on their needs, not as a finished piracy solution. In 2012 Google released a feature in Android 4.1 that encrypted paid applications so that they would only work on the device on which they were originally installed from the Google Play Store, but this feature has been temporarily deactivated due to technical issues.

Use outside of smartphones and tablets


The open and customizable nature of Android allows it to be used on other electronics aside from smartphones and tablets, including laptops and netbooks, smartbooks, smart TVs (Android TV, Google TV) and cameras (E.g. Galaxy Camera). In addition, the Android operating system has seen applications on smart glasses (Google Glass), smartwatches, headphones, car CD and DVD players, mirrors, portable media players, landline and Voice over IP phones. Ouya, a video game console running Android, became one of the most successful Kickstarter campaigns, crowdfunding US$8.5m for its development, and was later followed by other Android-based consoles, such as Nvidia's Shield Portable – an Android device in a video game controller form factor.

In 2011, Google demonstrated "Android@Home", a home automation technology which uses Android to control a range of household devices including light switches, power sockets and thermostats. Prototype light bulbs were announced that could be controlled from an Android phone or tablet, but Android head Andy Rubin was cautious to note that "turning a lightbulb on and off is nothing new", pointing to numerous failed home automation services. Google, he said, was thinking more ambitiously and the intention was to use their position as a cloud services provider to bring Google products into customers' homes.

Parrot unveiled an Android-based car stereo system known as Asteroid in 2011, followed by a successor, the touchscreen-based Asteroid Smart, in 2012. In 2013, Clarion released its own Android-based car stereo, the AX1. In January 2014 at Consumer Electronics Show, Google announced the formation of the Open Automotive Alliance, a group including several major automobile makers (Audi, General Motors, Hyundai, and Honda) and Nvidia, which aims to produce Android-based in car entertainment systems for automobiles, "[bringing] the best of Android into the automobile in a safe and seamless way."

On March 18, 2014, Google announced Android Wear, an Android-based platform specifically intended for smartwatches and other wearable devices; only a developer preview was made publicly available. This was followed by the unveiling of two Android Wear–based devices, the LG G Watch and Moto 360.

On June 25, 2014, at Google I/O, it was announced that Android TV, a Smart TV platform, is replacing the previously released Google TV. On June 26, 2014, Google announced Android Auto for the car.

Source: Wikipedia


Popular Posts