Solve Towers of Hanoi puzzle
You have a small collection of disks and three
piles into which you can put them
The disks all start on the leftmost pile,
and you want to move
them to the rightmost pile, never putting a disk on top of a smaller one.
The middle pile for intermediate storage.

Towers of Hanoi for Pocket PC is the Commercial version. The full version can be purchased by clicking on the "CLICK HERE TO ORDER" button below for around  10USD.