Version Timeline

The Android operating system began with the release of version 1.0 in September 2008. Since then the platform has been actively developed by Google with the addition of new features and several changes to the look and feel. Read more on Android history on the offical wikipedia page.

The release of each new OS version is tightly controlled by device manufacturers. Often customizations are added for better or worse, however a few devices support Google updates alone. This has lead to fragmentation of the OS with many devices left without updates. The development community on sites such as XDA and Cyanagen Mod develop custom ROMs for the latest Android OS. Will a little knowledge its possible to update your android device to the latest release.

Version	Major features/fixes
4.0 (Ice Cream Sandwich) Released 19 October 2011	Virtual buttons in the UI, instead of taking up a capacitive screen Voice typing, capable of recognizing speech and converting it into text Widgets in a new tab, listed in a similar list to apps Easier-to-create folders, with a drag-and-drop style A customizable launcher In a new phone app, visual voicemail functionality that lets user speed up or slow down voicemail messages Pinch-to-zoom functionality in the calendar Offline search, a two-line preview, and new action bar at the bottom of the Gmail app Ability to swipe left or right to switch between Gmail conversations Integrated screenshot capture (accomplished by holding Power and Volume-Down buttons) Improved error correction on the keyboard Ability to access apps directly from lock screen (similar to HTC Sense 3.x) Improved copy and paste functionality Better voice integration and continuous dictating capability Face Unlock, a facial recognition service Automatic syncing of browser with user’s Chrome bookmarks Modern Roboto font Data Usage section in settings that lets user set warnings when they approach a certain usage limit, and disable data when the limit is exceeded Ability to shut down apps that are using data in the background Camera app: zero shutter lag, time lapse settings, zoom while recording Built-in photo editor New gallery layout, organized by location and person Refreshed ‘People’ app with social network integration, status updates and hi-res images Android Beam, a NFC feature that lets user exchange websites, contact info, directions, YouTube, etc. Hardware acceleration of the UI Resizeable widgets Wi-Fi Direct
3.0 / 3.1 / 3.2 (Honeycomb) Released 22 February 2011	Easier access for apps to files on the SD card, e.g. for synchronisation Compatibility display mode for apps that have not yet been optimized for tablet screen resolutions New display support functions that give developers more control over the look and feel on different Android devices Connectivity for USB accessories Expanded Recent Apps list Resizable Home screen widgets Support for external keyboards and pointing devices Support for joysticks and gamepads Optimized tablet support with a new user interface Three dimensional desktop with redesigned widgets Refined multi-tasking Browser enhancements including tabbed web pages, form auto-fill, bookmark syncing with Google Chrome, and private browsing Support for video chat using Google Talk Hardware acceleration Support for multi-core processors
2.3 / 2.4 (Gingerbread) Released 6 December 2010	Google Wallet support for Nexus S 4G Support for voice or video chat using Google Talk Updated user interface design Support for extra-large screen sizes and resolutions (WXGA and higher) Native support for SIP VoIP telephony Support for WebM/VP8 video playback, and AAC audio encoding New audio effects such as reverb, equalization, headphone virtualization, and bass boost Support for Near Field Communication System-wide copy–paste functionalities Redesigned multi-touch software keyboard Enhanced support for native code development Audio, graphical, and input enhancements for game developers Concurrent garbage collection for increased performance Native support for more sensors (such as gyroscopes and barometers) A download manager for long-running downloads Improved power management and application control Native support for multiple cameras Switched from YAFFS to the ext4 filesystem
2.2 (Froyo) Released 20 May 2010	General Android OS speed, memory, and performance optimizations Additional application speed improvements courtesy of JIT implementation Increased Microsoft Exchange support (security policies, auto-discovery, GAL look-up, calendar synchronization, remote wipe) Improved application launcher with shortcuts to Phone and Browser applications USB tethering and Wi-Fi hotspot functionality Added an 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 Voice dialing and contact sharing over Bluetooth Support for numeric and alphanumeric passwords Support for file upload fields in the Browser application Support for installing applications to the expandable memory Adobe Flash 10.1 support Support for extra high DPI screens (320 dpi), such as 4″ 720p
2.0 / 2.1 (Eclair) Released 26 October 2009	Optimized hardware speed Support for more screen sizes and resolutions Revamped UI New Browser UI and HTML5 support New contact lists Better contrast ratio for backgrounds Improved Google Maps 3.1.2 Microsoft Exchange Server by Exchange ActiveSync 2.5 support Built in flash support for Camera Digital Zoom MotionEvent class enhanced to track multi-touch events Improved virtual keyboard Bluetooth 2.1 Live Wallpapers
1.6 (Donut) Released 15 September 2009	An improved Android Market experience An integrated camera, camcorder, and gallery interface Gallery now enables users to select multiple photos for deletion Updated Voice Search, with faster response and deeper integration with native applications, including the ability to dial contacts Updated search experience to allow searching bookmarks, history, contacts, and the web from the home screen 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 Gesture framework and GestureBuilder development tool Google free turn-by-turn navigation
1.5 (Cupcake) Released 30 April 2009	Ability to record and watch videos through camcorder mode Uploading videos to YouTube and pictures to Picasa directly from the phone A new soft-keyboard with text-prediction Bluetooth A2DP and AVRCP support Ability to automatically connect to a Bluetooth headset within a certain distance New widgets and folders that can populate the Home screens Animated screen transitions
1.1 Released 9 February 2009	Multiple resolved issues API changes Maps adds details and reviews Screen timeout longer when using speakerphone Show & Hide Dialpad included in-call menu Support for saving attachments from MMS Support for marquee in layouts
1.0 Released 23 September 2008