Japanese NURIKABE Puzzle

No guessing—ever. Every puzzle has exactly one solution. Turn numbers into islands, paint the rest into walls. A daily challenge, streaks, and fully offline.

Numbers are islands. Paint the rest into walls. That’s the whole rule—and the quiet satisfaction of a solved grid is hard to put down. Best of all, every puzzle here has exactly one solution. No guessing required.

What is Nurikabe? Each number is the size of a white “island.” Grow each island to exactly that many connected cells, then paint every remaining cell black to form the “wall.” Islands may never touch edge-to-edge, the wall must all connect into one region, and no 2×2 block of wall is allowed. From those constraints, you deduce the whole board with logic alone—a beloved Japanese pencil puzzle (a Nikoli classic).

Features • Always one solution: every generated board is solver-verified, so you solve by reasoning, never luck. • Four difficulties: Easy (6×6), Medium (8×8), Hard (10×10), Expert (12×12). • A daily puzzle: the same board for everyone each day, with streaks and a calendar. • Effortless input: tap to paint, drag to fill, long-press for walls—plus hint and undo. • Gentle assists: optional mistake highlighting and input-order settings. • Fully offline: play anywhere, no signal needed. Dark mode included. • A calm, ink-on-paper look.

Great for you if… • You’ve worn out Sudoku or nonograms and want the next challenge. • You’re tired of luck-based or ad-heavy puzzle apps. • You want a few clear-headed minutes on your commute or before bed. • You love pencil puzzles and appreciate an honestly built app.

Privacy & peace of mind • No account required. • All records stay on your device—nothing is sent to a server. • It works entirely offline.