IOS 4

iOS 4 is the 4th major release of iOS for the iPhone, iPod touch and iPad. It is for the iPhone (3G and 3GS) along with being available for the iPod Touch (2nd & 3rd Gen). The update is free and includes a multitude of new features. The features include, but are not limited to:


 * Multitasking
 * Folder Organisation
 * Multiple Mail Boxes
 * iBooks
 * support for iMovie (available in the App Store)
 * Creation of Playlists
 * 5x Digital Zoom for Camera (iPhone 4 and iPod Touch 4G)
 * LED flash (iPhone 4 only)
 * Tap-Focus for video
 * Picture Identification
 * Homescreen Wallpaper
 * Ability to 'Gift' Apps
 * Spell Check
 * Bluetooth Keypad
 * Ability to rent movies
 * Game Center
 * FaceTime (iPod Touch 4G and iPhone 4 only)
 * Personal hotspot

The iOS 4 round of updates has finished, it stated with iOS 4.0 and concluded with 4.3.5 which was released on July 25th 2011, it was preceded with the iOS 5 round of updates with iOS 5.0 being released on 12th October 2011.

Support
The 1st generation iPhone and iPod touch are not supported in this release. The iPhone 3G and 2nd generation iPod touch have limited support The iPad, 3rd and 4th generation iPod touch, iPhone 3GS, and iPhone 4 are all fully supported

Trivia

 * Initial release on iPhone 4.
 * Initial release on iPod touch 4.
 * This is the 1st release to drop support for some devices.
 * Recent version was un-available for the CDMA version of the iPhone 4.