This software is a part of the "WP8 remote administration" suite that has controls for keyboard, mouse, media center, youtube, powerpoint, file manager, skydrive and many many more. You can find link to the suite inside this app.
Gamepad emulator transforms your phone into a gamepad for pc games. It has 2 modes. Joystick mode and steering wheel mode (works with accelerometer).
Works with all type of games including Direct X games.
Both joystick and steering wheel mode are analogue. That means the more you steer your phone...the faster the car turns. Currently supports directional + 4 more buttons but more buttons will be added with updates.
Support multiple profiles for multiple computers. All keys are editable so they can be set for different computer games games.
You will find installation and setup directions inside the app.