This Privacy Policy explains what personal data Prost collects, why we collect it, how long we keep it, and the rights you have over it. Prost is operated from Germany and complies with the EU General Data Protection Regulation (GDPR).
The short version: we collect what the app needs to work, your sign-in identity, your session content (photos, venues, chats), and your location while a session is live so your crew can find you and you get your own route of the night. We don’t run ads and we never sell your data. The only analytics we use are anonymous usage statistics and crash reports (Firebase Analytics and Crashlytics), never tied to your account.
1 Who is responsible
Prost is operated by three individuals acting as joint data controllers, Derick David, Baran Ayaz and Aiden Dalley (collectively “The Prost Team”):
The Prost Team
Bürgermeister-Deichmann-Straße 31
28217 Bremen, Germany
Email: support@prosts.net
2 What we collect
2.1 Account data
Prost uses Sign in with Apple and Sign in with Google. When you sign in, we receive a unique account identifier and, depending on your provider settings, your name and email address. During onboarding you choose a username, which is your visible identity in Prost. We do not collect passwords.
2.2 Session content
When you start or join a Night session, the following is stored and shared with the other participants of that session:
- Session name, start/end times, and the list of participants
- Photos and videos captured with the Prost Camera or imported from your photo library
- Venue names, resolved from your location via the Google Places API, forming the night’s venue trail
- Sidequest content: the photo or video proof you capture for a quest and your crew’s confirm/reject votes
- Session chat messages (encrypted, see Section 2.5)
Your Recap card includes a short narrative caption generated using AI (Google Gemini), based on your session’s venue trail, timing, and a small number of session photos, so the Recap reads like a written memory of the night rather than a plain data summary. By starting or joining a session, you agree that a limited set of session photos may be processed by this AI for this purpose. You can edit or regenerate the caption from the Recap card at any time.
Session previews are public. Every session has a shareable link that opens a web preview showing the session name, current venue, participant names, venues visited, and session photos, visible to anyone who has the link, with or without the app. Share session links thoughtfully.
If your profile is set to public, content associated with your account (photos, videos, Recap cards) may also be used in Prost’s own marketing and promotional materials, see Terms of Service, Section 5.4. Set your profile to private in Settings to opt out of future selection.
2.3 Location data
Prost uses your precise location in four ways:
- Venue stamping: when you capture a photo, your location is used at that moment to resolve a venue name. We store the venue name string, not raw GPS coordinates, with the photo.
- Venue trail (background): while a session is active, and only if you grant location permission, Prost periodically records your position to work out which venue your group is at and to build the night’s venue trail for your Recap. With “While Using” permission this continues after you lock your phone, shown by your device’s location indicator, until the session ends or you close the app; with “Always” it also resumes if your device closes the app during the night. This continuous stream is never shown to other participants or displayed on any map.
- Your night route: the positions recorded during a session are also kept as your own route of that night, together with figures worked out from it (distance travelled, distance walked, time on the move). Your route is visible only to you. Other participants never see it; at most they see crew-wide totals for the night (for example, total distance travelled by everyone), which name no one and show no path.
- Session map check-ins: your location is shown to other participants on the session map only when you explicitly tap “Check In”. Nothing is shared automatically or continuously: each check-in is a single, one-time snapshot of your location at that moment, and the map shows how long ago each pin was last checked in so it’s clear when someone’s pin has gone stale. Before your first check-in each session, Prost asks separately whether you want to appear on the map at all, distinct from the operating-system location permission prompt; you can decline and still use every other part of the app. To help pins stay reasonably current, Prost may send you an occasional reminder notification asking you to check in again — tapping it is still a manual, one-time action, never an automatic share.
Users you have blocked never appear on your session map, and you never appear on theirs, in either direction.
Location collection (the background venue trail and any map check-ins) stops when the session ends, and live location data is automatically cleaned up by our servers; what remains is your own night route described above. We do not track your location outside of active sessions.
2.4 Device permissions
- Camera & microphone: to capture photos and videos with sound during sessions.
- Photo library: to import photos into a Recap and to save your Recap cards.
- Motion data: to tell whether you’re on the move or staying at a venue during a session, so location updates for your venue trail can slow down and save battery. Motion data isn’t stored on our servers.
- Notifications: we store a push notification token (Firebase Cloud Messaging) to deliver session and message notifications. You can disable notifications at any time in your device settings.
All permissions are optional and requested in context; denying them limits only the related feature.
2.5 Messages
Direct messages and session chat messages are encrypted with AES-256-GCM before being stored on our servers. Message content is not readable in plaintext at rest.
2.6 Social graph and stats
If you follow other users, we store your follow relationships and pending follow requests. We also derive aggregate stats from your sessions, nights out, unique venues visited, weekly streaks, to power your profile and achievements. These stats are never based on how much anyone drank.
2.7 Safety and moderation data
If you block or report another user, we store your block list and the report (reported account, reason category, and optional note) so our team can review it and enforce our Community Guidelines.
2.8 Analytics and diagnostics
Prost uses Firebase Analytics to record anonymous usage events (e.g. which onboarding step you’re on, or whether you added your photos to a night’s recap), and Firebase Crashlytics to record crash reports and error diagnostics when something goes wrong. Neither is tied to your name, email, or account identity, and neither is used for advertising. Crashlytics is disabled entirely in development builds.
2.9 What we do not collect
- No contact list or address book access
- No advertising identifiers, no ad networks, no ad-tech tracking pixels or SDKs
- No raw GPS history attached to your photos
3 Why we process your data (legal bases)
| Purpose | Legal basis (GDPR Art. 6) |
|---|---|
| Providing the app: accounts, sessions, Recaps, messaging | Contract performance, Art. 6(1)(b) |
| Session map check-ins | Consent, Art. 6(1)(a), given fresh by every individual Check In tap; withdraw at any time by simply not checking in again, or revoking the location permission in device settings |
| Background venue trail during sessions | Consent, Art. 6(1)(a), via your device’s location permission grant (“While Using” or “Always”); withdraw any time by revoking that permission in device settings |
| Your night route (your own location history) | Consent, Art. 6(1)(a), via the same location permission grant; withdraw any time by revoking that permission, and delete stored routes by deleting the night’s Recap or your account |
| Safety, moderation, abuse prevention | Legitimate interest, Art. 6(1)(f) |
| Marketing use of public-profile content (Terms §5.4) | Legitimate interest, Art. 6(1)(f); withdraw any time by switching your profile to private |
| Anonymous analytics and crash diagnostics | Legitimate interest, Art. 6(1)(f), improving app stability, onboarding and core features; no advertising identifiers, no cross-app tracking |
| Legal obligations (e.g. responding to lawful requests) | Legal obligation, Art. 6(1)(c) |
4 Who processes your data
Prost is built on Google Firebase (Google Ireland Ltd. / Google LLC), which provides authentication, databases, file storage, server functions, push notifications, and the analytics and crash-diagnostics described in Section 2.8, under data processing terms with us. Venue names are resolved through the Google Places API. Recap captions are generated using the Google Gemini API, which processes a limited set of session photos and session metadata (venue names, times, sidequest results) for that purpose only. Where data is transferred outside the EU/EEA, transfers are protected by the EU–US Data Privacy Framework and/or Standard Contractual Clauses.
We do not sell, rent, or trade your personal data. Ever.
5 How long we keep your data
- Session content: kept until you delete it. You can delete individual photos, Recap cards, or entire sessions in the app at any time.
- Live location: held only during an active session; removed when the session ends and swept by automatic cleanup.
- Night routes: kept as long as your Recap of that night. Deleted with that Recap or with your account, and included in your data export.
- Account data: kept while your account exists. When you delete your account, your data is permanently erased after a 30-day grace period (see below).
- Reports: kept as long as needed to handle the report and enforce our guidelines.
6 Deleting your account
You can delete your account at any time in the app: Profile → Settings → Delete Account. Deletion takes effect after a 30-day grace period, after which all personal data associated with your account is permanently removed in accordance with GDPR Art. 17. Full instructions are on our account deletion page.
7 Your rights
Under the GDPR you have the right to:
- Access the personal data we hold about you
- Correct inaccurate data
- Erase your data (“right to be forgotten”)
- Restrict or object to processing
- Receive your data in a portable format
- Withdraw consent at any time (e.g. revoke location permission in device settings)
To exercise any of these rights, email support@prosts.net. You also have the right to lodge a complaint with your local data protection authority; for Bremen, that is the Landesbeauftragte für Datenschutz und Informationsfreiheit der Freien Hansestadt Bremen.
8 Age requirement
Prost is for adults 18 and over. We do not knowingly collect data from anyone under 18. If we learn that a user is under 18, we terminate the account and delete its data. See our Child Safety Standards.
9 Security
Data in transit is protected with TLS. Direct messages are encrypted at rest with AES-256-GCM. Access to production data is restricted and controlled through Firebase security rules. No system is perfectly secure, if you believe your account is compromised, contact support@prosts.net immediately.
10 Changes to this policy
If we make material changes to this policy, we will notify you in the app at least 30 days before they take effect. The current version is always available at prosts.net/privacy.
11 Contact
Questions about privacy? Email support@prosts.net or write to the address in Section 1.