Privacy Policy for DeFog

Effective date: July 9, 2026

DeFog ("we", "our", "the app") is a walking-exploration app that reveals a fog-covered map of the real world as you physically walk, and lets you compare your explored distance with other players on a global leaderboard. This Privacy Policy explains what information the app collects, why it collects it, and how it is used, stored, and shared.

By using DeFog, you agree to the collection and use of information described in this policy.

1. Information We Collect

1.1 Account information

When you sign in, DeFog uses Google Sign-In. We receive and store your:

Google account ID (unique identifier)
Name
Email address
Profile photo URL

We do not receive or store your Google account password.

1.2 Location information

Prominent disclosure: DeFog collects precise (GPS) location data, including in the background while the app is closed or not in active use, in order to continuously reveal the fog-of-war map and track the distance you walk, even when you are not actively looking at the app. A persistent notification is shown whenever background location tracking is active, and you can stop it at any time from the app or from your device's system settings.

Specifically, we collect:

Precise location (foreground): used to show your position on the map and update the fog-of-war effect in real time while the app is open.
Precise location (background): used to keep tracking your walked path and exploring new map tiles while the app is minimized or the screen is off, so your progress isn't lost when you're not looking at your phone.

Your raw GPS coordinates are converted into a set of coarse map "tiles" (~11 x 11 meters each) representing areas you have explored, plus a cumulative walked distance. We do not build or store a continuous, timestamped trace of your exact movements beyond what's needed for these two derived values.

1.3 Gameplay & progress data

Explored map tile identifiers (derived from location, see above)
Total distance walked, in kilometers
World exploration percentage
Your rank and score on the global leaderboard

1.4 Search queries

If you use the in-app place search, your search text is sent to OpenStreetMap Nominatim, a free, independent, third-party geocoding service, in order to return matching places. This request is not linked to your Google account or any other personal identifier.

1.5 Approximate place name

DeFog uses your device's on-device geocoding service (Android's Geocoder API) to turn your current coordinates into a human-readable place name (e.g. city / country) shown on the home screen. On most devices this is handled locally or via Google's geocoding backend, depending on your device manufacturer.

2. How We Use Your Information

To operate the core fog-of-war exploration feature and show your progress on a map
To calculate and display your walked distance and world-exploration percentage
To calculate your position on the global leaderboard and let you compare progress with other players
To identify your account and keep your progress in sync across sessions and devices
To provide customer support if you contact us

We do not use your data for advertising, and DeFog does not display third-party ads.

3. Public Leaderboard Disclosure

Your display name and total walked distance are shown publicly to all other users of the app on the global leaderboard. Your exact location, explored tiles, and email address are never shown to other users.

4. Third-Party Services

DeFog relies on the following third-party services to function. Each has its own privacy policy governing how it handles data on our behalf:

Firebase Authentication & Cloud Firestore (Google) — account sign-in and cloud data storage
Google Maps SDK for Android — displaying the map
Google Play services Location — obtaining GPS location
Google Sign-In — authentication
OpenStreetMap Nominatim — place search

5. Data Storage & Security

Your account, gameplay, and leaderboard data are stored on Google Cloud infrastructure via Firebase (Cloud Firestore), protected by Google's industry-standard security measures and Firestore access rules. We take reasonable technical and organizational measures to protect your information, but no method of electronic storage is 100% secure.

6. Data Retention

We retain your account and progress data for as long as your account is active, so you can keep your exploration history across sessions and devices. You can request deletion of your account and all associated data at any time (see "Your Rights" below).

7. Your Rights & Choices

Access: you can request a copy of the data we hold about you.
Deletion: you can request permanent deletion of your account and all associated data (profile, explored tiles, walked distance, leaderboard entry).
Location permission: you can revoke location permission (including background location) at any time from your device's system settings. DeFog's core exploration feature will not work without it.
Sign out: you can sign out of your Google account from within the app at any time.

To exercise any of these rights, contact us using the details below.

8. Children's Privacy

DeFog is not directed at children under the age of 13, and we do not knowingly collect personal information from children under 13. If you believe a child has provided us with personal information, please contact us so we can delete it.

9. Changes to This Policy

We may update this Privacy Policy from time to time. Any changes will be posted on this page with an updated effective date. Continued use of the app after changes are posted constitutes acceptance of the updated policy.

10. Contact Us

If you have any questions about this Privacy Policy, or want to request access to or deletion of your data, contact us at:

Email: REPLACE_WITH_YOUR_EMAIL@example.com