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 instruction leaflet, but as with many newer iPod models the battery in the first generation iPhone has been soldered in. Therefore, a soldering iron is required to install the new battery. The iPhone 3G uses a different battery fitted with a connector that is easier to replace. The iPhone X features a different battery, with two battery cells, and the adhesive pull tabs are adhered to the sides instead of folded over the top, therefore making repairs a little more difficult than before. A patent filed by the corporation, published in late July 2013, revealed the development of a new