This app is a tool to aid you in completing the cryptograms you might find in your daily newspaper. You supply the puzzle, and substitute letters in by tapping on the screen. This free version contains no cryptograms of its own -- you enter them. The software itself is just an alternative to pen-and-paper solving.
The size and padding of the letters is customizable, so if you find that your tapping aim is off, you can increase the target area.
If you can think of ways to improve this app without taking away the fun and challenge of deciphering cryptograms, I'd love to hear about them via email.