Loopline
A calm, painted take on Slitherlink. Join the dots into one single loop so every number touches exactly that many lines. Simple to learn, satisfying when it clicks.
What's in Loopline
Logic puzzles with no pressure, a lot of polish and no ads.
A puzzle every day
Solve the daily puzzle, build your streak, and come back tomorrow for a fresh one.
Journey
60 levels across painted scenes of the Scottish coast. Earn up to three stars on every level, then go back and beat your best.
Weekly Challenge
Five puzzles and one scored attempt a week. Quick and clean wins, and hints cost you time.
Hints that help
A gentle nudge first, then the next move if you need it. Hints point at the real next step.
Learn by playing
A short interactive tutorial teaches the rules and the tricks in about two minutes.
Made to relax
No ads, no subscription, light and dark mode, and zoom on the bigger boards.
Play free to start. A one-time purchase, Loopline+, unlocks unlimited practice puzzles, unlimited hints and the archive of past daily puzzles.
Support
Stuck, or found a bug? Email hello@cosmolabs.co.uk and tell us your iPhone model and iOS version.
How do I play?
Draw one single closed loop along the grid lines. A number says how many of the four sides around it are part of the loop. The loop never branches, crosses itself or has dead ends. You can replay the interactive tutorial any time from Settings, under How to play.
How do I draw and mark lines?
Tap an edge to draw a line. Tap it again to turn it into an x, which means "not a line". Tap a third time to clear it. On 7x7 and 10x10 boards you can pinch with two fingers to zoom and drag with two fingers to move around.
How do stars work?
Three stars means you finished with no hints and no failed Checks. Use two hints or fewer for two stars. Any finished puzzle earns at least one. Your best stars for each level are kept, and replaying never lowers them.
How does the Weekly Challenge work?
You get one scored attempt per week. Once you start you can't restart, but you can leave and pick up where you stopped, and the clock only runs while a puzzle is on screen. Your score is your time plus 30 seconds per hint and 20 seconds per failed Check. Lower is better.
How do I restore my purchase?
Open Settings and tap Restore Purchases. Use the same Apple account you bought with. If it still doesn't unlock, email us and we'll sort it.
How do I switch between light and dark mode?
Open Settings and choose System, Light or Dark under Color scheme.
Does Loopline collect my data?
No. Your progress stays on your iPhone. Read the privacy policy for the details.