Forstall was also responsible for creating a software development kit for programmers to build i Phone apps, as well as an App Store within i Tunes.
Each page of a folder can contain up to nine apps, and there can be 15 pages in total, allowing for a total of 135 apps in a single folder.
Originally, i Pod Touch users had to pay for system software updates.
This was due to accounting rules making the device not a "subscription device" like i Phone or Apple TV, and significant enhancements to the device required payments.
The home screen appears whenever the user unlocks the device or presses the physical "Home" button whilst in another app.
Before i OS 4 on the i Phone 3GS (or later), the screen's background could be customized only through jailbreaking, but can now be changed out-of-the-box.