Proven Sudoku
Features / Pencil marks and hints
Pencil marks, hints and undo, built for one hand
Everything you need to work a board, and a hint that refuses to solve it for you.
The problem
Most sudoku help is all or nothing. Either you get no support at all, or you press hint and the app fills a square, which ends the bit you came for. Neither is what a stuck player actually wants.
How it works
Notes let you pencil the numbers a square could be. Placing a number clears it from the pencil marks of every square it can see, so the grid tidies itself as you go. Undo and redo step through your moves. The check button marks every number in the wrong spot, and counts as help in the same way a hint does, so a solve that used it is not recorded as unaided. A hint names the kind of step available next and never where it is. Usually it is telling you that you have not missed anything clever. On a keyboard the arrows move, 1 to 9 fill, backspace clears, and N toggles pencil marks.
Image to add: The board toolbar, showing notes, undo, redo, check and hint. The repository holds no product screenshots yet, only the 68 technique diagrams, so nothing is shown here rather than something invented.
What you would use it for
Get unstuck without being told the answer
Knowing the next step is a hidden single is enough to start looking again. Where it is stays yours to find.
Keep an honest record
Hints and checks both count as help, and the stats keep a separate best for solves that used neither.
Play on a phone or a keyboard
The controls are laid out for one thumb, and every one of them has a keyboard equivalent.
Learn how to use it
How to play walks through the controls step by step.
Related
- Difficulty you can trustEach level is defined by the hardest technique a board really needs, and every board is checked before anyone sees it.
- Your statsYour times are kept for good, unlike the boards, so you can see whether you are actually getting faster.
- The daily puzzleThree boards a day, the same three for every player in the world, new at midnight UTC.