iOS (formerly iPhone OS prior to June 2010) is Apple Inc.'s mobile operating system, originally developed for the iPhone.
It has been extended to support other Apple devices such as the iPod Touch, iPad, and Apple TV.
Unlike Windows CE (Mobile and Phone) and Android, Apple does not license iOS for installation on non-Apple hardware.
On March 6, 2012 Apple's App Store contained more than 550,000 IOS applications, which collectively have been downloaded by more than 25 billion times.
It had a 16% share of the smartphone operating system units sold in the last quarter of 2010, behind both Google's Android and Nokia's Symbian.
In May 2010 in the USA, it accounted for 59% of mobile web data consumption (including use on both the iPod Touch and the iPad).