With Apple having announced the iPhone OS 4.0 on Thursday, some of the greatly needed features – including multitasking, a unified e-mail in-box and home screen folders – will now come to the popular iPhone.

The iPhone OS 4.0 is not exactly a kind of update that its predecessor iPhone OS 3.0 was; and since it is currently only a developer release, chances are that Apple will probably introduce some changes when the OS is finally released in summer this year. Moreover, Apple will also release Game Center later this year.

With multitasking being one of the most hyped features of the iPhone OS 4.0, Apple has specified that the iPhone 3GS, the iPod Touch, and the newly-launched iPad will support a limited form of multitasking – whereby, instead of allowing full third-party programs to run in the background, seven background services will be available to iPhone developers.

The app developers would essentially have to hit upon a combination of the seven background services being offered by Apple, so as to create an adroitness that would make their programs seem like running behind the scenes.

The seven background services include - background audio; Voice over IP; location services; push notifications; local notifications; task completion; and fast app switching.