Fukurou Sudoku

A clean sudoku. No ads, no account, no data collection.

Five levels that actually differ

Difficulty here is not about how many digits are missing — it is about what kind of thinking a grid demands. Every puzzle is checked before it reaches you, and each level asks for something the one before did not:

• Owlet — opening its eyes
• Owl — sees in the half-light
• Night Owl — corners its prey
• Night Hunter — nothing escapes it
• Athena’s Owl — knows before it looks

Every puzzle has exactly one solution and can always be solved by logic. Never by guessing. The top two levels start with 21–25 digits and call for pairs, triples, wings and chains.

Help, in moderation

A classic game gives you a few tips — three by default, you choose how many. A tip lights one cell and names its digit, no theory: the cell an experienced solver would find next, not one at random. If there is a wrong digit on the board, it tells you that first.

Assisted play, if you want it

On the first two levels, a switch under the grid: wrong digits in red, counters on the keypad, automatic note cleanup, unlimited help. Its statistics are kept apart from classic play.

The basics, done properly

• Pencil marks
• Unlimited undo and redo
• Start the same puzzle over whenever you like
• The game saves itself — close it whenever you like
• A timer that stops when you leave the app
• Statistics per level, day streaks, time distribution
• Light and dark themes
• Greek and English

For every screen

Phone, tablet and foldables. On wide screens the grid sits beside the controls instead of growing pointlessly. On foldables nothing lands on the crease.

What it does not do

No ads. No tracking. No account. No in-app purchases. No internet connection needed to play.

The app touches the network in exactly one place: if you press “check for fixes” in Settings. Never on launch, never in the background.