IPhone OS 2 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
IPhone user to have options to decline a phone call when a person is calling them. The user can reply with a message, or set a reminder to call them back at a later time. The layout of the music library is similar to that of an iPod. The iPhone can sort its media library by songs, artists, albums, videos, playlists, genres, composers, podcasts, audiobooks, and compilations. Options are presented alphabetically, except in playlists, which retain their order from iTunes. The iPhone uses a large font that allows users plenty of room to touch their selection. Users can rotate their device