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 accessories for phone calls and voice control of certain devices. Users can adjust volume, control music and video playback (play/pause and next/previous,) and record voice memos on supported iPod and iPhone models and Mac computers. There have been many reports of moisture problems with the remote/mic earbuds. The original iPhone and iPhone 3G came with the iPhone Stereo Headset, a push-button and microphone on the right side of the headphones (there is no volume control, and only limited control of calls). A series of docks released for the iPhone 5, 5s, and 5c, were announced and released on September 10, 2013.