A little room to think. Classic Sudoku for iPhone and iPad.
Open Play, then Saved games. Progress saves automatically on your device. Enabling iCloud in Settings makes recent checkpoints available to your other Apple devices. Opening a remote checkpoint creates a separate local copy.
Select a cell, enable Notes, then choose digits. Guide first shows where to look, then explains the reasoning. You decide whether to apply the step. Undo and redo are available.
Choose Paper or Chalkboard in Settings. Use Large number keys or Focus view for bigger controls. Rotate iPad to place the tools beside the board.
On Today, choose Browse past days to revisit the past year. Reminders are optional; completing today's puzzle cancels its upcoming reminder. Open the app periodically to refresh the next 60 days of reminders.
Sign into the same Apple account on both devices and enable iCloud checkpoints inside Quiet Sudoku. Choose Sync now, then refresh Saved games. Your local progress remains available while offline.
Operator: Jintao Lv. Report an issue on GitHub / 提交问题. A GitHub account is required. Issues are public: include app version, device model, and steps to reproduce only. Do not include account details, passwords, private screenshots or personal contact information.