Stopko: Logic Grid Puzzles

Stopko is a logic puzzle you finish by reasoning. You get a short story, a grid and a list of clues, and from those you can work out who has what. Without guessing once.

Every one of the 400 puzzles was checked by the solver that built it. The solver proved two things: that exactly one answer fits, and that you can reach it by pure deduction. No clue is spare either — cover any one of them and the puzzle can no longer be solved.

What is in Stopko:
• 400 puzzles across five chapters, from three categories up to five
• six themes with their own story: a café, allotments, a block of flats, a race, a library, a market
• a hint that first names the clue which settles the next square, and only fills the square in if you press it again
• automatic crosses, undo, and a higher contrast mode for reading the grid
• English, Slovak and Czech

The app contains no ads, needs no account, and works offline.

The optional Night Observatory adds 60 new deduction puzzles with a one-time purchase. The original 400 puzzles and hints stay free.