During the release of iOS 7, Apple included a way for developers to create game controller add-ons for the phone. They existed only for a while, they are basically cases with buttons that clamp on to the back of your phone– but they were not officially sanctioned by Apple, until the release of iOS 7.
Logitech’s first gamepad (probably) had an image of an accessory-maker which was leaked by usually spot-on gadget-uncoverer, evleaks. This version of Logitech model could be the first release of a number of gamepads.
Gamepads are rather unique in this sense because they are an improvement over the way many mobile games are controlled right now. iPhone games are made using controllers, then later brought to the iPhone. Gamepads are actually the solution of many problem of Apple developers.