Square One: Daily Sudoku

Square One brings daily Sudoku, guided solving, and fresh puzzles into a calm, focused space. Play solo offline, share a puzzle with a friend, or start a live race with SharePlay on iPhone. LEARN AS YOU SOLVE A short illustrated guide introduces the rules. During a puzzle, Learn explains a logical next step on your board. Practise Naked Singles, Hidden Singles, Naked Pairs, and Box-Line reductions at your own pace. A PUZZLE FOR EVERY DAY Solve the daily board, build a streak, and review your completed daily puzzle. Choose Easy, Medium, Hard, or Expert for a new board whenever you like. Every generated puzzle has one solution. MAKE IT YOURS Use pencil notes, smart highlighting, zoom, undo, and hints. Track solve times, scores, achievements, and technique progress. Earn coins by completing distinct puzzles, then use them to unlock color themes and alternate app icons. Preview a theme before choosing it. CHALLENGE A FRIEND Share a puzzle link or QR code so someone else can try the same board and beat your time. On supported iPhones, SharePlay lets you solve the same board together in a live race. YOUR PACE, YOUR SPACE Solo puzzles work offline. Square One has no ads, no third-party analytics, and no account system of its own. Puzzles and settings are stored on your device. If you sign in to Game Center, some progress and achievements may sync across your Apple devices. Optional reminders are scheduled on your device.