LEA Extended Input - iOS/Android app with windows server to control functions in games via your smartphone/tablet.
Macro Deck - Use smartphone as macropad for pc
aGamepad - aGamepad allows you to use your Android based phone as gamepad for Windows.
TouchPortal - Touch Portal is a companion app to control a PC or a Mac by using a deck of buttons to improve the workflow & productivity of game streamers, content creators and professionals.
Gamepad Joystick MAXJoypad - Play PC games using your smartphone or tablet as gamepad, joystick or racing wheel.
Unified Remote - Unified Remote is a software app available for iPhone, Android, and Windows Phone mobile operating systems. It's designed to turn your smartphone into a universal remote. Read more about Unified Remote.