Lantern Sudoku

Lantern Sudoku is a quiet sudoku for short, calm sessions. It has no ads, no account and no game over, and it works fully offline.

When you're stuck, a hint lights the next step instead of giving the answer away. You choose how much help you want: • Where to look: the area where the next step is. • Why: the technique by name, with a short explanation and the cells that matter highlighted. • The digit, only if you want it. If a digit on the board is wrong, the hint tells you that first, so you never chase a step built on a mistake.

Honest puzzles • Four levels: Easy, Medium, Hard and Expert. • Every puzzle has exactly one solution and never needs guessing. • Each puzzle is graded by the hardest technique it needs, so a level means the same thing every time. • More than 11,000 puzzles come with the app. Nothing is downloaded.

A daily puzzle • One puzzle a day, the same for everyone, with a streak and days played. • Share a spoiler-free result card if you like. Nothing is shared unless you tap Share.

Made to be easy on the eyes • Large, clear digits, with a Larger digits option. • Light, Dark and two high-contrast themes. • Works with large system text and with TalkBack.

Never punished • Mistakes can be shown or hidden. A mistake limit is optional and off by default. • Your game is saved after every move. Undo, redo, erase and notes that tidy themselves when you place a digit. • A calm summary when you finish, and statistics per level.

Private by design • No ads, no analytics, no crash reporting, no account. • The app asks for no permissions, not even internet access. • Your games stay on your phone. If Android backup is on, Android may copy them to your own Google account; the app itself never uploads anything.

Lantern Sudoku is free and open source software (GPL-3.0-or-later).