One of the advantages of Mobile Gamepad compared to other similar Android apps (which do exist) is that it allows you to set up different profiles for different games. You can configure the keys of your Android device for different games, so that you only have to go through that process once.
Another very interesting feature is that you can use your device's accelerometer for driving and simulation games. Thanks to this features, you can tilt your phone to move a vehicle from left to right, which is an effect that is similar to what you would have with a steering wheel.
Mobile Gamepad is an excellent way to take advantage of an Android device when you are going to play on your computer. With the exception of games that need very precise controls, the experience that you will get with Mobile Gamepad is more than satisfactory.