IPod games are in the form of .ipg files, which are actually .zip archives in disguise. When unzipped, they reveal executable files along with common audio and image files, leading to the possibility of third party games. Apple has not publicly released a software development kit (SDK) for iPod-specific development. Apps produced with the iPhone SDK are compatible only with the iOS on the iPod Touch and iPhone, which cannot run clickwheel-based games. All iPods except for the iPod Touch can function in "disk mode" as mass storage devices to store data files but this may not be the default behavior.
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