OpenTrailPaper
Open Source Eink Bike GPS
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
Turn your DIY e-paper head unit into a full bike computer — plan routes, create workouts and sync rides over Bluetooth. No account, no cloud, and completely open source.
OpenTrailPaper is the free companion app for the OpenTrailPaper e-paper bike computer — an open-source, sunlight-readable head unit you build yourself. The app handles everything that's awkward on a touch e-paper screen: planning routes, building offline maps, and reviewing your rides. Then it sends it all to your head unit over Bluetooth. No account, no cloud, no subscription.
PLAN ROUTES — Search for any destination, preview the route on the map, and send it to your device as a GPX file. Turn-by-turn prompts guide you along the way — and your head unit follows the route even with no SD card and no signal.
OFFLINE MAPS — Pick the area you ride and the app bakes offline map tiles straight onto the device's SD card. Roads, water, and parks render on the e-paper display wherever you go — no data connection required, ever.
REVIEW YOUR RIDES — Pull your recorded rides off the device and see distance, moving time, speed, elevation gain, power, and heart rate, with your track drawn on the map. Every ride is a standard .fit file you can export and open anywhere.
TUNE YOUR DEVICE — Adjust FTP, time zone, units, and backlight, and pair Bluetooth heart-rate and power sensors — all from your phone. Settings are saved to the device's flash so they persist across reboots. When a new firmware build is ready, update over the air with one tap.
BUILT TO STAY OUT OF THE WAY
- Works completely offline once set up — no phone or signal needed on the bike
- No account and no subscription, ever
- Nothing is uploaded; your routes and rides stay on your own devices
- Fully open source
WHY LOCATION AND BLUETOOTH — Bluetooth connects the app to your head unit to sync routes, maps, settings, and rides. Location (only while you're using the app) shows your position on the map, warm-starts the device's GPS so it locks on faster, and acts as a backup fix when the device can't see the sky.
OpenTrailPaper pairs with the DIY OpenTrailPaper head unit. Build instructions, firmware, and full source are on GitHub.
Ratings & Reviews
- This app has not received enough ratings or reviews to display an overview.
the workout release:
- builder/import/edit (including editing workouts already on the device)
- dashboard editor with drag-and-drop pages, music support and the new workout page.
The developer, Raemond Bergstrom-Wood, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Provider
- Raemond Bergstrom-Wood
- Size
- 3.6 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later.
- iPhone
- Location
- This app may use your location even when it is not open, which can decrease device battery life.
- Age Rating
4+
- 4+
- Copyright
- © 2026