FOG is a walking map app that turns everyday movement into a lasting record of places explored. Inspired by the “fog of war” in video games, its map begins covered, then permanently reveals streets and locations as users walk across them. The app works in the background, including with the phone screen off, and records collected countries, regions, cities, and landmarks. Users can also import past activity from Google Timeline exports or GPX files to reveal walks from previous years.

FOG is free to explore, with a one-time $5.99 purchase unlocking additional ranks, characters, and history imports; there is no subscription. The company emphasizes privacy: maps remain on the phone, with no account, cloud storage, analytics, or ads, and users can export their data. The app also creates shareable cards showing a user’s walking record, route shape, and earned items. Its website offers guides to 131 cities and information about festivals, including schedules, walking advice, and local places to eat.