The iPhone OS 2 (later named iOS 2) was released on July 11, 2008, and the final version, iOS 2.2.1, was released on January 27, 2009. It was succeeded by iPhone OS 3 on June 17, 2009. So, the active support and update period for iOS 2 lasted less than one year, from its initial release in July 2008 until the next major version release in June 2009.

iOS 2 was the first version to support third-party apps via the App Store and was available on the first-generation iPhone and iPhone 3G.