A free program for Android, by Fishstix.

GamePad is an app that will enable you to use your phone as a controller when playing games. It can emulate various keyboards or pads, such as an 8-way directional pad and simple D-Dpad directional keys. It is compatible with DosBox Turbo and other emulators including OnLive and SplashTop.

How to use:

First, you must install the app on your Android device.

Then, go to the Keyboards section in the Android settings, and enable “GamePad”.

That’s it! It is very simple and easy. Once you’ve done that, you can already use the app and enjoy a lot of features. These include a built-in transparent keyboard, multi-touch capability, and more.