Nine: Sudoku That Explains

Every sudoku app has a hint button. You press it, a digit appears, and you have learned nothing. Next time you are stuck in the same place.

Nine does it differently. You get one explanation per puzzle, and it fills in nothing. It names the technique, highlights the row, column or box where the proof is, and spells out the reasoning:

"ONLY PLACE. In the bottom right box the 7 can only go here. The 7s in row 8 and column 9 rule out the other cells."

"POINTING PAIR. In the bottom right box the 5 can only go in row 8. So the 5 is out everywhere else in row 8. That leaves column 2 with only one place for the 5: here."

Then you place it yourself. You learn something instead of being handed the answer.

THE PUZZLES
Four difficulty levels, 30 levels each. Difficulty does not come from the number of given digits, but from the techniques needed to solve: from lone digits to triples and X-wing. Every puzzle is verified to have exactly one solution. Guessing is never required.

THE EIGHT TECHNIQUES
Only option, only place, pointing pair, box claimed, naked pair, hidden pair, naked triple and X-wing. Together they solve every puzzle in Nine. Each one has its own page with an example board where you see it happen, and when an explanation uses one you tap its name to read what it is.

THE RULES
Three mistakes and the puzzle restarts. One explanation. Three stars if you finish without either.

A NEW ONE EVERY DAY
Everyone gets the same daily puzzle, with Sunday as the hardest, just like the newspaper. Your streak sits on the home screen.

ALSO
• Notes, undo, automatic saving
• Your own times and statistics per difficulty
• Light and dark mode
• Dutch, English, French, German, Turkish, Spanish and Portuguese

TRY IT FREE
Play everything free for 7 days. After that, unlock Nine with a one-time purchase, no subscription. Nothing is ever charged automatically.

WHAT IS NOT IN IT
No ads. No account. No subscription. No internet needed to play. The app collects nothing and sends nothing: your progress lives on your device and nowhere else.

Made in Belgium by Made by Balthazar.