IPhone OS 2 available to the iPhone and iPod Touch. Prior to the public release of iPhone OS 2.0, Apple held a keynote event to announce the iPhone OS Software Development Kit ("SDK") to developers. The most notable feature of iPhone OS 2 was the App Store. Before this feature was introduced, the only way to install custom applications on the device was via jailbreaking, which is strongly discouraged and unsupported by Apple. There were 500 applications available for download at the launch of the App Store, though this amount has grown dramatically since then. Now, the App Store has more than 2
IPhone 3GS There are two ways to activate Voice Control: hold the Home button while in the home screen for a few seconds; or, change the effect of what double-clicking the home button does so it will activate Voice Control (only on iOS 3.x; on iOS 4 or later, double clicking the Home button opens the multitasking bar). VoiceOver, Color Inversion, and Text Zoom were introduced as exclusive features to the iPhone 3GS. VoiceOver is a feature that dictates music details, system menus, text, and other things which was first introduced on the third generation iPod shuffle. Color inversion reverses the color