<b>Note:</b> The developer marked this project as "no longer being actively maintained" on 2016-04-06, so you should rather use it's succesor https://f-droid.org/packages/org.moire.opensudoku. OpenSudoku is a simple sudoku game. It's designed to be controlled both by finger and keyboard. It's preloaded with 90 puzzles in 3 difficulty levels. More puzzles can be downloaded from the web and it also allows you to enter your own.