It is the operating system that powers many of the company's mobile devices, including the iPhone. It was also used on iPads (introduced: January 2010; availability: April 2010) until iPadOS was introduced in 2019, and on the iPod Touch devices, which were discontinued in mid-2022.[12] It is the world's second-most widely installed mobile operating system, after Android. It is the basis for three other operating systems made by Apple: iPadOS, tvOS, and watchOS.[13]