Paint every region with four colours so neighbours sharing an edge never match. Fixed diamond clues guide fifteen uniquely solvable 10, 16 and 24-region maps. Colour symbols, pencil notes, live border conflicts, pointer and keyboard controls, undo, assisted hints and local saves. Source: https://github.com/chrisboyle/sgtpuzzles/blob/d1e10eb57dd80af4999e698a9ab31f546e9a0b9d/app/src/main/jni/map.c (MIT).

border-atlas-four-colours.skillsafe.ai

Run app here

PricingCompletely free

Security scanClean — skill and frontend scanned

Source chrisboyle/sgtpuzzles

Created2026-10-26

Updated2026-10-26

Every public app is built from a security-scanned skill and must pass a clean scan — skill and frontend — before it can be listed. Have a skill of your own? Turn it into an app — or read the step-by-step walkthrough.