Glint · for iPhone
Light Up (Akari), the logic puzzle you can feel
Drop a lamp on an open square and light pours along its row and its column until a wall stops it. The rule is easy to see and quietly deep to solve — and in Glint every move has its own feel under your finger.
How to play Light Up (Akari)
Light Up, also known as Akari, is a logic puzzle from the Japanese puzzle publisher Nikoli. The board is a grid of open squares and walls, and some walls carry a number. You place lamps on open squares: a lamp lights its own square and shines along its row and its column until a wall or the edge of the board stops it.
- Light every squareEvery open square must end up lit.
- Keep lamps out of each other's sightNo two lamps may shine on each other along a row or column.
- Obey the numbersA numbered wall has exactly that many lamps on its four sides.
What it looks like
How to solve Light Up
Glint's own solver makes these three deductions before it tries anything else. Repeat them until nothing changes.
- One lamp per stretchA lamp rules out every other square of its row and its column up to the nearest wall or the edge — a second lamp there would see it.
- Finish the numbersOnce a number has all its lamps, its other neighbours stay empty, so nothing goes next to a 0. If the squares still free around it are exactly as many as the lamps it still needs, each of them gets one: a 4 has a lamp on every side, and so does a 3 against the edge.
- One way to be litIf a dark square can be lit from only one position, the lamp goes there.
Never guess: every board in Glint has exactly one solution, so reasoning alone always gets you there.
Daily, and shareable
A new puzzle arrives every day — the same one for everyone, gentle early in the week and tighter by the weekend. Past the daily there are sixty more boards in five packs, each checked for a single fair solution. Finish a board and Glint folds it into a QR code: a friend points a camera at it and plays the very same board, with no sign-up.
Two more puzzle games from the same developer: Loopling, a time loop puzzle where your teammate is a recording of you, and Orikomi, origami puzzles where you slide the paper onto a fixed fold line.
Free to play, one unlock for the rest
The daily puzzle and the first two packs are free for good. A single one-time unlock opens packs 3–5 and adds two haptic packs and three colour themes.
Honest about the limits
- No ads, no account. It plays happily with no signal.
Last reviewed 22 October 2026