The iOS 2 (originally called iPhone OS 2) was released on July 11, 2008. It debuted alongside the iPhone 3G and introduced the App Store, enabling official support for third-party applications on the iPhone and iPod Touch. It was a major update from iPhone OS 1, available as a free upgrade for iPhone users and for a fee on the iPod Touch at that time.
If the question is about the current iOS version or a different iOS release date, please specify.
