Cairn is a hiking app for alpine routes in Switzerland and northern Italy. The first version opened on a feed of trip reports. Almost nobody read them.
We rebuilt the app around the map. It opens where you are, shows the routes you can finish before dark and keeps working with no signal. A turnaround time sits at the top of every route and counts down as you walk.
The app is written in React Native with offline tiles stored on the device. Route data syncs from a small editorial tool the Cairn team uses to check every trail each season.
