Japanese NURIKABE Puzzle

Numbers are islands. Shade the rest into walls.
Every puzzle has exactly one solution, so you never have to guess.
And when you're stuck, the hint tells you why the next move works.

WHAT IS NURIKABE?
Each number is the size of a white island. Grow every island to exactly that many connected cells, then shade everything else black to form the wall.
- Islands never touch edge to edge
- The wall is one connected region
- No 2x2 blocks of wall
A classic Japanese pencil puzzle, also known as Cell Structure. If you enjoy sudoku, nonograms or other logic grids, you'll feel right at home.

FEATURES
- Solver-verified: every generated board has exactly one solution
- Four levels: Easy 6x6, Medium 8x8, Hard 10x10, Expert 11x11
- Hints that explain: instead of revealing a cell, each hint says why the next move is forced, like "This island matches its number, so everything around it is wall."
- Daily puzzle: the same board for everyone, with streaks
- Ranks from 10 Kyu to Meijin that grow with every solve
- Auto-save: pick up an unfinished board from the home screen
- Rule cues: finished islands dim, and 2x2 walls show up as you play (optional)
- Fast input: tap to cycle wall, dot and blank, drag to shade a run, long-press to toggle a wall. Undo, Redo and Clear
- Stats: puzzles solved, average time, no-hint solves and per-level results
- A calm ink-on-paper look, with dark mode

GREAT FOR YOU IF
- You've worn out sudoku or nonograms and want a new challenge
- You're tired of luck-based or pushy puzzle games
- You want a few clear-headed minutes on the commute or before bed
- You love pencil-and-paper logic puzzles

PRIVACY
- No account needed
- Your records, rank and boards in progress stay on your device and are never sent anywhere
- Puzzles play without a connection
- To show other apps from the same developer, the app may load public App Store information such as app names and icons