Every variant, one app.
A curated iOS app for killer, thermo, arrow, German whispers, XV and more. A daily challenge with a leaderboard, an advanced hint engine, and offline solving — no ads, no trackers.
What's inside
Built for variants
Killer, thermo, arrow, German whispers, XV, Kropki and more — variant rules are first-class, designed in from the ground up.
Advanced hint system
Stuck on a step? A variant-aware hint engine reads your pencil marks and walks you through the next logical deduction with clear animations — never just "here's a digit."
Daily challenge & leaderboard
A fresh puzzle every day, with a Game Center leaderboard that ranks clean solves by time. Come back daily and climb.
Offline solving
Solve anywhere. Your progress, pencil marks, and full undo history stay on device — no connection needed.
No ads, no trackers
Free to play, with an optional Variant+ subscription. Your gameplay is never sold or turned into telemetry.
Search that gets it
Find puzzles by rule, constraint, or theme. Semantic search understands "killer with thermos" or "gentle arrow" — not just exact tags.
Learn the variants
New to variant sudoku? Start with a plain-English rules guide — each one covers how the variant works and the techniques that crack it.
Acknowledgements
Puzzle generation, validation, and difficulty research use CP-SAT techniques and Interactive Sudoku Solver (ISS) by sigh as offline analysis tools. ISS is MIT licensed.
Shout-out to Logic Masters Germany, Sven from SudokuPad, and Cracking the Cryptic for their influence on the variant sudoku community.