History of iPhone
On January 9, 2007, Steve Jobs announced iPhone at the Macworld convention, receiving substantial media attention. Jobs announced that the first iPhone would be released later that year. On June 29, 2007, the first iPhone was released.
IPhone OS 2
iPhone OS 2.0 became available on July 11, 2008 with the release of the iPhone 3G. Devices running 1.x are upgradable to this version. This version of iOS introduces the App Store, making third-party applications available to the iPhone and iPod Touch. Prior to the public release of iPhone OS 2.0, Apple held a keynote event to announce the iPhone OS Software Development Kit ("SDK") to developers.The most notable feature of iPhone OS 2 was the App Store. Before this feature was introduced, the only way to install custom applications on the device was via jailbreaking, which is strongly discouraged and unsupported by Apple. There were 500 applications available for download at the launch of the App Store, though this amount has grown dramatically since then. Now, the App Store has more than 2 million apps as of 2016.