OS 4 IPhone

iPhone OS 4 CompatibilityiPhone OS 4 will work with iPhone 3G, iPhone 3GS, and the second- and third-generation iPod touch this summer, and with iPad in the fall. Not all features are compatible with all devices. For example, multitasking is available only with iPhone 3GS and the third-generation iPod touch (32GB and 64GB models from late 2009).With iPhone OS 4, iPhone owners will enjoy over 100 new features that make it easier to interact with apps, manage email, read books, and more. New features include the following:

Multitasking

Developers will have access to seven multitasking services, which will allow tasks to be performed in the background while preserving performance and battery life. So you’ll be able to make a Voice over IP call while playing a game or checking email, find a restaurant on Urbanspoon while listening to Pandora, and more.

Folders

Organize apps into folders with drag-and-drop simplicity. Get faster access to your favorites and browse and manage up to 2160 apps at once — many more than the current limit of 180 apps.