How to play

The rules

Fill the 9×9 grid so every row, every column and every 3×3 box contains the numbers 1 to 9 exactly once. Some numbers are given at the start. Every puzzle in the game has exactly one solution.

Starting a game

On the start screen, tap New game and choose a difficulty: Easy, Medium, Hard or Expert. Your game saves after every move, so Continue game takes you straight back to it.

Controls

• Tap a cell, then tap a number to fill it in.
• Notes: turn on Notes to write small pencil marks instead of answers. Tap the same number again to remove it.
• Swipe across cells to select several at once, then tap a number to add that pencil mark to all of them.
• Undo steps back one move. Erase clears the selected cell.
• Pause with the button next to the timer.

Wrong entries aren’t corrected for you, but a hint will point them out so you can review them.