678KKReasoned

Take a quiet break with a number logic puzzle built around careful deduction. Each row, column, and outlined region follows one rule: do not repeat a number.

Choose 6 × 6 grids across the Beginner and Advanced chapters, or 9 × 9 grids in Expert. Each chapter contains 20 puzzles generated from valid grids and checked for a unique solution. A date-based daily challenge is selected on your device and works offline.

Select an empty square to enter an answer, or switch to candidate mode to keep small notes. Related rows, columns, and regions are easy to follow on the board. Check marks duplicate entries without revealing answers. Each puzzle offers up to three hints, with an explanation of the deduction behind each one.

Undo and redo restore answers and candidate notes together. Pause, return home, or leave the app and continue later with your board and timer saved. Starting clues cannot be changed, notes never count as answers, and a puzzle is complete only when the full grid is valid.

Review your finish time, undo actions, hint use, and fastest recorded times by board size. Track chapter completion, finishes without hints, daily challenge dates, and consecutive local challenges. Choose a light, dark, or system theme and adjust sound, vibration, board motion, conflict markers, and candidate counts.

Progress and preferences stay on your device. No account or network connection is needed to play.