FogBound

About the Project

FogBound started from a simple observation: maps are great at telling you where things are, but not whether you actually know a place. We wanted to flip that idea and build a map based on familiarity instead of destinations. The core concept is a fog-of-war style map that clears as you move through the world, revealing both the paths you’ve taken and nearby points of interest only after you’ve explored the surrounding area.

Over the course of the hackathon, we learned a lot about balancing performance, UX, and restraint. We built FogBound as a mobile app using Expo and React Native, handling location tracking on-device and storing exploration data locally for speed and reliability. Points of interest are fetched from OpenStreetMap and cached, then conditionally shown based on whether the surrounding area has been explored. A lot of effort went into making sure the app felt calm and responsive rather than noisy or overwhelming.

The biggest challenges were performance and scope control. Rendering fog dynamically at different zoom levels required careful optimization, and we had to think hard about how much information to show without breaking the exploration feel. We also learned when not to add features—avoiding feeds, routes, and checklists helped keep the experience focused on curiosity instead of completion. Overall, FogBound taught us how thoughtful constraints and small design decisions can shape how people interact with everyday spaces.

Built With

• expo.io
• express.js
• mongodb
• node.js
• openstreetmap
• react-native
• react-native-maps
• sqlite