A free program for Android, by Verschueren Geert.

Are you into games that can test your critical thinking skills? Do you want to play something that will exercise your arithmetic capabilities? The PolyMath app is simply the answer to these.

In this game, you will have to solve certain equations by getting the appropriate values in their rightful places. You will have to be good at addition and multiplication in order to pass through the levels.

The difficulty gradually increases as you go through each level. Once you finish all of them, the game will provide you with random numbers and shapes to complete, giving you endless math enjoyment.