A free program for Android, by Pro Active App.
The Sudoku Shelf is a free app for all ages.
It's an application with a user-friendly interface, which lets you play Sudoku offline.
You will get all the required options, which will allow you to choose between the four available Sudoku puzzle modes (4x4, 6x6, 9x9, and 12x12) and the five difficulty levels.
You will also get the option to use the hint function, which will allow you to find the missing numbers.
You can check your progress and see your score.
The application also has a statistics section, which will show you the time spent on this game and the number of errors made.
