Your data stays yours

Privacy Policy

Last updated: July 20, 2026

Anonymous analytics onlyJust an anonymous usage count — no personal data, no location, no ads.

No account to use itSign-up is only needed to unlock ZYRNTOPO Pro.

Local storageAll maps and data live on your device.

Foreground GPS onlyLocation is never accessed in the background.

The short version: ZYRNTOPO runs on your device, not on our servers. The only thing the app itself sends us is an anonymous usage ping (the app version, the platform, and a random device identifier — no personal data, no location, not linked to any account), and the core app requires no account. Network traffic is between your device and the third-party map, weather, and routing providers you choose to use (listed in full below) — plus, only if you buy ZYRNTOPO Pro, our own account and license service. That optional account is the one place we store personal data on a server we operate. This policy should be read together with our Terms of Use.

Overview

ZYRNTOPO is an offline mapping app for backcountry travel, field work, and search and rescue. We are committed to protecting your privacy. This policy explains what data the app collects, how it is used, and your rights.

Data Collection

The core ZYRNTOPO app does not collect, transmit, or store personal data on servers operated by us. The one exception is the optional ZYRNTOPO Pro account, described in its own section below. Some optional online features contact third-party map, weather, elevation, routing, or search providers directly from your device. In summary:

The only usage data collected is an anonymous install ping — a random device identifier the app generates locally, the app version, and the platform (web or Android). It contains no personal information and no location, is not linked to any account, and is never used for advertising or shared. See Anonymous Usage Analytics below.
No personal information is sent to servers operated by us, except the email and password you provide if you create an optional ZYRNTOPO Pro account.
No account or sign-up is required to use the core app.
No cookies are used for tracking purposes.

Anonymous Usage Analytics

To understand how many people use ZYRNTOPO — including those who never create an account — the app sends a single, minimal, anonymous usage ping to our own service (api.zyrntopo.com) roughly once per day. This ping contains only:

a random identifier the app generates and stores on your device the first time it runs (it is not derived from your device, hardware, phone number, advertising ID, or any account, and you can clear it at any time by clearing the app's data);
the app version; and
the platform (web or Android).

That is the entire payload. It contains no personal information, no location, no map activity, and no account link. We use it only to count installs, active devices, and which app versions are in use. It is never used for advertising, never sold, and never shared. The request reaches our server over HTTPS; your IP address is visible to the server for that connection (as with any web request) and is used only to prevent abuse — it is not stored alongside the ping. This is the only telemetry the app sends; there are no third-party analytics SDKs, cookies, or advertising trackers in ZYRNTOPO.

Local Data Storage

All app data — including map objects, settings, gear lists, and team rosters — is stored locally on your device using browser storage (IndexedDB / localForage). Map tiles viewed are cached locally using the Cache API for improved performance.

Network Requests

The app makes network requests to third-party services to load maps and optional field context. These providers may receive standard request information such as your IP address, browser or Android WebView user agent, referrer/origin where applicable, timestamp, and the requested URL. Map tile URLs contain tile coordinates for the area being viewed; weather, elevation, route-planning, and search requests may include the map/GPS coordinates or search query needed to answer that request.

Third-party services used by online features may include:

OpenStreetMap (tile.openstreetmap.org)
OpenTopoMap (tile.opentopomap.org)
OpenFreeMap — vector basemaps (tiles.openfreemap.org)
VersaTiles — vector basemaps (tiles.versatiles.org)
Esri ArcGIS (server.arcgisonline.com)
CartoDB (basemaps.cartocdn.com)
Wikimedia Labs — Hillshade (tiles.wmflabs.org)
OpenSnowMap (tiles.opensnowmap.org)
BLM GIS (gis.blm.gov)
USFS (apps.fs.usda.gov)
Mapterhorn DEM (tiles.mapterhorn.com)
Nominatim Geocoding (nominatim.openstreetmap.org)
BRouter routing (brouter.de)
Open-Meteo / OpenTopoData / Open-Elevation for weather and elevation lookups
NWS Weather (forecast.weather.gov)

The app also contacts ZYRNTOPO's own static endpoints (hosted on Cloudflare) to check whether a newer app version is available and to sync the optional community points-of-interest database. These are plain file downloads and contain no personal data about you; as with any web request, the host receives standard information such as your IP address, user agent, and timestamp.

GPS / Location Data

If you grant location permission, the app accesses your device's GPS to display your position on the map, record tracks, follow routes, and provide navigation features. Location is accessed only while the app is in use (foreground) — the app does not access your location in the background. Location data is stored locally on your device unless you export it, share it with a Team Sync session, or use an online feature that needs coordinates, such as weather, elevation, routing, or map/search requests. Before the system location prompt is shown, the app displays a disclosure explaining this use.

Microphone

If you grant microphone permission, the app can record short voice messages (up to 60 seconds) for use in the Team Sync chat feature. The microphone is requested only at the moment you start recording a voice note. Voice messages are transmitted directly to other connected team members in the same session via the active sync transport (P2P, LAN, or Reticulum mesh). They are not sent to any server operated by us, not stored on external systems, and are not retained after the session ends.

Photos

You can attach a photo to a map waypoint. Photos are chosen through your device's standard file / photo picker (which may offer your camera) — the app itself does not request camera permission and never accesses the camera directly. Attached photos are stored locally on your device within the app's data storage. They are never uploaded to any server or shared externally without your explicit export action.

When you join a Team Sync session, your device's GPS coordinates and shared map objects are sent to other connected team members in that session. Depending on the transport you choose, this data may travel peer-to-peer, through a WebRTC signalling provider, through a LAN WebSocket bridge, or through a Reticulum mesh bridge. It does not pass through any server operated by us. Team Sync is opt-in — you must explicitly start a session and share a session code or QR code with others to connect. No location data is retained by us after the session ends.

ZYRNTOPO Pro Accounts and Licensing

The core app is free and needs no account. ZYRNTOPO Pro — an optional one-time purchase that unlocks the advanced features — does use an account, and it is the one place ZYRNTOPO stores personal data on a server we operate. If you never create a Pro account, none of this applies to you.

When you create a ZYRNTOPO Pro account, we run a self-hosted account and license service (at api.zyrntopo.com) that stores:

Your email address, encrypted at rest, used to sign in, to send password-reset and purchase-confirmation emails, and to tie your Pro license to you.
A hashed password — we use a one-way hash (Argon2id) and never store your password in readable form.
Your Pro license status and the signed license token issued to your account.

We do not require your name, phone number, or address, and we do not sell or share this information. Your Pro license is verified on your device using a public key built into the app, so once Pro is active it keeps working with no signal and without contacting our server.

Payments. Purchases are handled by a third-party payment processor (such as Lemon Squeezy) or by the app store you bought from. You enter your payment card details with that processor — they are never seen or stored by us. The processor shares back only what we need to grant your license, such as your email and confirmation that payment succeeded.

Your control. From the account page you can change your email or password, transfer your Pro license to another account, download a copy of your account data, or permanently close your account and delete its data.

Third-Party Services

The app does not integrate with any third-party analytics, advertising, or social media services.

The website may load basic presentation assets from third-party CDNs, including Google Fonts and Font Awesome, and may link to Google Play or Buy Me a Coffee. Those providers may receive standard request information such as your IP address, browser user agent, referrer, and timestamp when your browser requests their assets or opens their links. These services are not used by us for analytics or advertising.

The homepage shows an approximate local weather chip. To do this, your browser makes a request to an IP-geolocation service (ipwho.is) to estimate your city from your IP address, and to a weather service (Open-Meteo) for current conditions near that location. This runs in your browser, the result is not stored, and it is used only to display the weather chip — not for analytics or advertising. The account and Pro pages communicate with our license service (api.zyrntopo.com), described above.

Children's Privacy

ZYRNTOPO does not knowingly collect any data from children under 13.

Changes to This Policy

We may update this privacy policy from time to time. Changes will be reflected on this page with an updated date.

Contact

If you have questions about this privacy policy, contact us at [email protected].