Our Sudoku App auto generates puzzles - which means you will never run out of puzzles to solve!
You can choose from a number of difficulty levels to match the game to your skill
It also supports 'marks' so you can record possible numbers on each cell
Unlimited Undo / Redo makes it easy to go back if you get into a pickle
And if you make a mistake, the duplicates will be highlighted
Note: Sometimes you might end up with a board which has two solutions- specialy at more difficult levels when much of the board is empty to start with, but all boards are guaranteed solvable. This should not matter as you can solve to either legal solution.