Privacy Policy
Last updated: July 16, 2026
Asteroid Audiobook Player is an ad-free hobby project. Asteroid does not run any servers and does not operate a backend that receives, stores, or redistributes your audiobook library. Your audio files live on your device and in the cloud folders you choose with your cloud data provider (for example Dropbox or OneDrive). Optional sync of progress and bookmarks may use Google Drive App Data when you enable that feature. The app does not sell your personal data.
1. Local storage & library access
Asteroid indexes and plays audiobooks from library folders you select under Settings. Audiobook file contents are processed locally for playback and tagging. To support offline listening and restoring app state, the app may cache downloaded audio, metadata, cover images, playback progress, bookmarks, and related app data on your device.
Asteroid does not send file contents to Asteroid—there are no Asteroid servers to receive them.
2. Cloud storage & optional Google sync
You may connect cloud providers such as Dropbox or OneDrive for your audiobook library. Those services use their own sign-in flows; credentials stay on your device and are sent only to that provider's official APIs—never to an Asteroid server.
Optional cross-device sync of listening progress and bookmarks may use Google Sign-In with limited Drive scopes, in particular drive.appdata (hidden app data for sync JSON). The app does not request drive.file or full Drive access for the audiobook library. Credentials and tokens for Google stay on the device and are passed only to Google's APIs.
3. Book metadata lookup (Open Library)
Asteroid analyzes audiobook folder names, file names, and embedded media metadata locally to identify possible book titles, authors, and identifiers. When metadata lookup runs (Resolve), selected search terms may be sent directly from the device to third-party metadata providers, such as Open Library, to retrieve matching book information and cover artwork.
Asteroid does not send audiobook file contents, cloud-storage credentials, your name or email, or a single dump of your entire library index to the developer's servers (there are none). Lookups go from your device to the metadata provider. That provider may receive technical information normally associated with an internet request, including the device's IP address, request time, and each search query. Over time, many queries from the same IP could suggest which titles were looked up. That is not the same as knowing your identity, but it is not fully anonymous.
Metadata and cover references returned by Open Library are stored in your local index so the app does not repeat the same lookups every time you browse. You are responsible for using Open Library data in accordance with Open Library's terms and policies.
When Open Library does not provide a confident match, the app may optionally query Google Books (where enabled). Use of Google Books data must comply with Google Books API terms.
4. Analytics and crash reporting
To keep the app stable, anonymous crash reports and aggregated usage statistics may be sent via Google Firebase Crashlytics and Firebase Analytics—for example device model, OS version, stack traces, aggregated listening time, and approximate library size. These reports do not include audiobook titles or your library contents. They are never sold.
Firebase Analytics may use the device Advertising ID so Google can measure app performance, usage, and related analytics (for example install attribution). Asteroid does not show ads, does not use the Advertising ID to sell advertising, and does not sell that identifier or analytics data to third parties for advertising.
5. Supporter contributions (Google Play)
Optional Supporter Status is handled through Google Play Billing (monthly supporter subscription and/or one-time supporter contribution). Payment processing is performed by Google; we do not receive your payment card details.
6. Children's privacy
The app does not knowingly collect personal information from children. It is designed to work with files and accounts you control. Metadata lookups and crash reporting work as described above.
7. Contact
Questions about this policy: asteroid@jlundmark.org