iOS 2, originally called iPhone OS 2, is the second major release of Apple's iOS mobile operating system. It was launched on July 11, 2008, coinciding with the release of the iPhone 3G. This version was the first to support third- party applications through the introduction of the App Store, making it a significant milestone in iOS history. It included new features like push email, enhanced Mail app capabilities, multiple calendar support, scientific calculator in landscape mode, parental controls, and MobileMe integration. iOS 2 was available as a free update for iPhone users and as a paid update for iPod Touch users at the time, but it was later succeeded by iPhone OS 3 in June 2009. Supported devices included the first-generation iPhone, iPhone 3G, and the first and second generation iPod Touches.
