Android 4.0 – codenamed Ice Cream Sandwich – was previewed at the May 2011 Google I/O event, and officially launched at the Galaxy Nexus and Ice Cream Sandwich release event on 19 October 2011. The SDK for Android 4.0.1 was publicly released on 19 October 2011. Google's Gabe Cohen stated that ICS was "theoretically compatible" with any Android 2.3.x device in production at that time.The source code for ICS became available on 14 November 2011, three days before the Galaxy Nexus was released. New features included:
- Enhanced speed and performance
- Virtual buttons in the UI, in place of capacitive or physical buttons
- Separation of widgets in a new tab, listed in a similar manner to apps
- Easier-to-create folders, with a drag-and-drop style
- A customizable launcher
- Improved visual voicemail with the ability to 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 down the 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, real-time speech to text dictation
- Face Unlock, a feature that allows users to unlock handsets using facial recognition software
- New tabbed web browser, allowing up to 16 tabs
- Automatic syncing of browser with users' Chrome bookmarks
- Modern Roboto font
- 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 apps that are using data in the background
- Improved camera app 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' app 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
- Hardware acceleration of the UI
- Resizeable widgets – already part of Android 3.1 for tablets, but new for cellphones
- Wi-Fi Direct
- 1080p video recording for stock Android devices
Samsung Galaxy Nexus with Android 4.0.1 - Screenshots :-