MOGA has an iPhone compatible gamepad in the works, and leaked photos of it suggest it could come with a built-in battery. You can see the pictures posted by @evleaks over on Mac Rumors. The controller, according to the report, is powered by a 1800mAh battery, and compacts when not in use. Apple announced in June it would start supporting third-party controllers with iOS 7. Have a look at it through the link. Via Polygon.