Offline first
A feature is not done until it works with no connection, or says clearly that it needs one.
Company
ZYRNTOPO and ZYRN Workstation are made by Grange Dev Group in Washington State, where plenty of places still have no signal.
About
ZYRNTOPO is built around one idea: the map has to keep working when the phone has no bars. So the maps, terrain, tools and your own data live on the device, and the app uses a connection when there is one instead of waiting for it.
That led to a field app for Android, Windows, Linux and the web, ZYRN Workstation for the desk, and Team Sync, a self-hosted TAK server, local network discovery and mesh radio support to connect them. Everything exports to common file formats, so your data never gets stuck.
We build for search and rescue teams, field crews, emergency managers, drone operators and people heading into the backcountry. We list what ships, mark what is in beta, and say plainly where data goes.
Principles
A feature is not done until it works with no connection, or says clearly that it needs one.
Your data exports to common formats, and the app works with the tools teams already use.
Available, beta and planned mean different things, and we label every feature that way.
Support
Field reports shape every release. The more detail you give, the faster we can fix it.
Getting started, offline maps, terrain, Team Sync, TAK and import and export.
Read the documentationQuestions, field notes and feature requests, answered by the people who build the software.
Visit the forumTell us what you did, what you expected and what happened instead. Screenshots help.
Report a problemSend the details and how to reproduce them, and give us a chance to fix it before you publish.
Email a security reportContact
Looking at ZYRNTOPO for a SAR unit, an agency or a field team? Tell us how many devices and which platforms you need, and we'll tell you what works today.
Data sources
The renders on this site are computed in your browser from the sources below. The app credits each of its providers in the map attribution.
| Data | Source | License | Used for |
|---|---|---|---|
| Elevation | USGS 3D Elevation Program, through the Tilezen terrain tiles on the Registry of Open Data on AWS | Public domain | 3D terrain, contours, slope, viewshed and profiles |
| Imagery | USGS The National Map aerial imagery | Public domain | The imagery basemap in the renders |
| Glaciers, trails, peaks and the route | © OpenStreetMap contributors | Open Database License | Labels, glacier outlines, trails and the Disappointment Cleaver route |
| Product screenshots | ZYRNTOPO and ZYRN Workstation | © Grange Dev Group | Device figures |