Zebra vs Stopko

Read a clue. Cross off what it rules out. Watch the consequences ripple until one arrangement survives. Zebra is a logic-grid game — the classic "the doctor lives in the red house" puzzle — built around a generator that proves every board before it reaches you. There is exactly one solution, it is always reachable by reasoning, and you are never asked to guess. TIERS THAT NAME THE TECHNIQUE Four difficulty tiers, each named after the reasoning it asks for rather than a vague star rating: cross off, chain, work out before-and-after, test a possibility. The generator computes the exact deduction depth each case requires, so the label is measured, not asserted. WHY YOU'LL STAY • A new case every day, the same one for everyone, generated offline • A streak to protect and a spoiler-free result to share • A free archive: replay any past case from its seed • Hints reveal the next real deduction and name the clue behind it WRITTEN, NOT MACHINE-TRANSLATED The clues ARE the puzzle, so they are composed natively in all five languages — English, German, Arabic, Persian and Kurdish (Sorani) — with proper right-to-left layout, localized numerals, and fonts that actually cover the Kurdish letters ڕ ڤ ڵ ۆ ێ ە. MADE TO BE COMFORTABLE • No timer, no lives, no energy meter • Never colour as the only signal • Fully offline. No account, no sign-up FREE, HONESTLY The daily, the archive, streaks and stats are free with light optional ads. Rewarded video is opt-in and only ever buys a hint. No banner ads on the board, ever. One purchase removes ads forever — no subscription.

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 and no purchases, needs no account, and works offline.