# Privacy Policy for 406DF
Last updated: February 26, 2026
406DF ("we", "our", or "us") provides the 406DF mobile application (the "App").
This Privacy Policy explains what information the App processes, how it is used, and your choices.
## 1. Information the App Processes
### a) Location data (Precise Location)
- The App requests access to your device location while you use the App.
- Location is used to:
- show your current position on the map,
- center/recenter the map,
- capture burst start points.
### b) Heading/orientation data
- The App reads device heading/orientation to support heading-up map mode and burst direction calculations.
### c) Map and offline map data
- The App uses Mapbox services/SDK to display maps and download offline map regions.
- Downloaded offline map data is stored locally on your device.
### d) User input
- The App processes burst bearing values you enter.
## 2. What We Do Not Collect
Within the App itself, we do not require account registration and we do not intentionally collect:
- your name, email address, phone number, or mailing address,
- contacts, photos, microphone, camera recordings, or health data,
- advertising identifiers for ad targeting.
## 3. Third-Party Services
The App uses Mapbox to provide map rendering and offline tile delivery.
When Mapbox services are used, technical/network information and map/location-related requests may be processed by Mapbox under their own terms and privacy policy.
Mapbox Privacy Policy: https://www.mapbox.com/legal/privacy
## 4. How Information Is Used
We use processed data only to operate app functionality, including:
- showing maps and your location,
- calculating and displaying burst lines/intersections,
- downloading and managing offline map regions.
We do not use App data for behavioral advertising or cross-app tracking.
## 5. Data Storage and Retention
- Offline map files remain on your device until removed.
- You can remove offline map files using the App's "Remove Map Data" action.
- Burst lines and related calculations are kept in app state and are not designed as long-term cloud records by the App.
## 6. Your Choices
You can:
- deny or revoke location permission in iOS Settings,
- remove offline map data at any time from within the App,
- stop using the App at any time.
If Mapbox telemetry/usage controls are shown in attribution/privacy controls, you may use those controls as provided by Mapbox.
## 7. Children's Privacy
The App is not directed to children under 13, and we do not knowingly collect personal information from children under 13.
## 8. Changes to This Policy
We may update this Privacy Policy from time to time. Updated versions will be posted at the published policy URL with a revised "Last updated" date.
## 9. Contact
If you have privacy questions, contact:
- Name: Yunxia Liu
- Email: thomas.yunxia.liu at gmail.com