Inkstone Sudoku

One deduction at a time.

Inkstone brings Sudoku to a quiet paper-and-ink setting. Explore six Classic difficulty tiers, from a gentle Sprout puzzle to Fiendish chains and fish. Mini 6×6 and Diagonal boards offer a different rhythm.

Every bundled puzzle has one solution and a verified logical path. When you need a hand, free teaching hints name the technique, show the pattern and explain the next step. Practice nineteen techniques in short lessons.

Choose your helpers: pencil notes, color marks, automatic note removal, mistake checks and a timer you can hide. Undo and redo your entries, resume unfinished pages, or switch to a dark theme. Three daily puzzles and a calendar let you build a regular habit.

Keep progress with local saves and a backup code. No account is needed to play.

Advertisements never interrupt puzzles or lessons. Occasional ads may appear after completed puzzles. An optional one-time Remove Ads purchase can be restored through Google Play.

Features: 2,200 original puzzles; 57 practice positions; free hints; Mini and Diagonal variants; three daily difficulties; notes and paint; undo/redo; dark themes; portrait and landscape; statistics; sixteen local achievements.