A free program for Android, by Zero Logic Games.

Minimal Sudoku is an addicting logic game, which is free to play and available on your mobile device. All you need to do is to fill a 9×9 grid with numbers 1-9, without overlapping or repeating any numbers in the same row, column, or block. The challenge is to do it without any errors.

The app has 4 different difficulty levels, so it’s easy to start and play with no difficulty. You can enjoy casual play, but if you want an extra challenge, you can also use the app’s timer feature to see how quickly you can solve the puzzles.

You can check your score and challenge your friends, worldwide.