Play classic 9×9 Sudoku offline on iPhone and iPad. Choose from Easy to Expert and enjoy a clean, high‑contrast board with smart hints, notes (pencil marks), undo/redo, and optional error/same‑number highlights. Pause and track your time as you learn and improve—no account required. Track achievements and detailed stats, customize themes, sounds, and haptics with volume controls, and rely on auto‑save (plus manual save) so progress is always preserved. Features ・Classic 9×9 Sudoku — fully offline; Easy, Medium, Hard, and Expert ・Clean, high‑contrast grid with same‑number and optional error highlighting ・Notes (pencil marks) with auto‑remove for confirmed numbers ・Adjustable hint limit with an in‑game counter ・Timer toggle, pause, and “Perfect Game” tracker ・Second Chance: watch a short ad to continue after Game Over (one mistake left) ・“Give Up” to reveal the full solution for learning ・Achievements and detailed statistics (difficulty, time, win rate) ・Multiple themes; sound and haptics with volume control ・Auto‑save plus manual save option; no account required