Sudoku Master: Classic Puzzle

Sudoku, done properly — graded by how a puzzle actually plays, not just its clue count. Evil means you'll need advanced techniques throughout; Easy means singles all the way down. What the tier says is what you get. WHAT MAKES IT DIFFERENT • Hints that teach — every hint names the technique it uses and shows you why, instead of silently filling a cell. Spot the same pattern yourself next time. • Real difficulty grading — five tiers, Easy through Evil, graded by how often a puzzle actually demands advanced thinking, not just whether it can once. • The hint button never dead-ends — every puzzle is checked against a full logical solver before it ships, so a hint is always there when you need one. • Daily Challenge — one puzzle a day, a streak worth protecting, and a two-year calendar to look back on. • Play your size — 4×4, 6×6, or full 9×9 boards, each with difficulty tiers that actually make sense for that size. • Two ways to play — tap a cell then a digit, or tap a digit and paint cells with it. Switch anytime in Settings. • Notes that clean up after themselves — placing a digit clears it from every pencil mark that can no longer use it. • Zen mode — no timer, no mistake limit, just the puzzle. • Light, dark, and sepia themes. • Per-difficulty stats and personal best times. No ads in your very first session — full stop. After that, ads are paced deliberately: never right after a rewarded video, never before you've actually seen your win screen. Built to respect your time: short to load, quick to resume, and honest about what it's asking of you.