Beamdoku

One lighthouse per zone. Never two in the same row or column, and never touching. That's the whole rule — and every grid is solvable by pure logic, never by guessing. Place a lighthouse and its beam lights up the row and the column. Two beams cross? Everything turns red until you fix it. Solve the grid and the whole coast lights up. FEATURES • 60 hand-verified levels that grow from 4×4 to 8×8, then 176 more grids for experts • A daily puzzle, the same for everyone, every day • Name the port: each level reveals a letter of a famous US lighthouse harbor — Boston, Nantucket, Key West… Guess it to bank extra hints • Hints that never spoil: they only remove a wrong lighthouse or reveal one missing • Long-press to mark a square you've ruled out • Haptic feedback, a soft pentatonic soundtrack you can mute, and a reminder for tomorrow's daily puzzle if you want one • Works fully offline. No account. No ads, ever. Unique solution guaranteed on every grid.