A free program for Android, by Joerg Jahnke.

Mobile Sudoku is an excellent app that will help you hone your skills, challenge yourself, and track your progress. Its intuitive interface and unlimited number of Sudoku boards make it an ideal pastime for people of all ages and skill levels. 

The free app allows you to track your scores and compare them with other players, giving you the perfect opportunity to sharpen your Sudoku skills. Plus, you can play it anywhere on your phone using either your touchscreen or keyboard. 

So, why not download Mobile Sudoku now? It’s a great way to have fun and improve your skills at the same time.