Freakpad

Freakpad is an android app which can transform your android smartphone into a game controller of your PC. You can add custom joystick to control your mouse or arrow keys of keyboard. You can add buttons too on your smartphone screen which can perform certain actions like making keyboard key presses or mouse clicks. Further more you can use your device's accelerometer to perform actions, like if you tilt your device left then you can make press of left arrow key of keyboard or `A` key of keyboard.

Here's how the magic can be done:
Step 1 : Download Freakpad App on Your Smartphone
Step 2 : Download Freakpad Server on your PC from the following link
Windows : https://drive.google.com/open?id=0B_VrMwIzXp5sSmN5RXE3WDlJTXc
Linux: https://drive.google.com/open?id=0B_VrMwIzXp5sVmNWbERQcGhaWUk
Mac: https://drive.google.com/open?id=0B_VrMwIzXp5sUXZNZjZpbE9fMzQ

Step 3: Download And Run the application on your respective operating system.
Step 4: Click on start server. (Note : Allow access to public and private network if prompted by OS)
Step 5: Get your computer's IP Address
Step 6: Open Freakpad on Smartphone > Settings > Set Your PC's IP Address
Step 7: Begin adding your game profile and controls.
Step 8: Head to the playground ;)