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Effective Date: December 28, 2025
Last Updated: July 29, 2026
This Privacy Policy describes how Libris ("we", "us", or "our") collects, uses, and shares information when
you use our mobile application ("App"). We are committed to protecting your privacy and ensuring
transparency about our data practices.
1. Information We Collect
1.1 Information You Provide
- Google Account Information: When you sign in with Google, we receive your email address
and basic profile information (name, profile picture) to enable cloud synchronization.
- Reading Content: E-books, PDFs, and documents you add to the app are stored locally on
your device and optionally in your personal Google Drive.
- User Preferences: Reading settings, bookmarks, highlights, annotations, and notes you
create.
1.2 Automatically Collected Information
- Reading Statistics: Pages read, reading time, and session data for your personal
statistics dashboard (stored locally).
- App Analytics: Screen views and feature usage to improve app experience (stored
locally).
- Device Information: Device model, operating system version, and app version for
troubleshooting purposes.
1.3 Third-Party Data Collection
Google AdMob with Ad Mediation: Our app displays advertisements through Google AdMob with
ad mediation. AdMob may collect device identifiers, IP address, and usage data to serve personalized ads.
The mediation platform may share data with multiple ad networks to optimize ad delivery. You can opt out of
personalized advertising in your device settings.
iOS App Tracking Transparency (ATT): On iOS 14.5 and later, our app requests your
permission to track your activity across other companies' apps and websites for advertising purposes. If you
grant permission, your advertising identifier (IDFA) may be used to deliver more relevant ads. If you deny
permission, you will still see ads, but they may be less relevant and not personalized to you. You can
change your tracking preference at any time in your iOS Settings > Privacy & Security > Tracking.
Ad Mediation Partners: We use the following ad networks through Google AdMob's mediation
framework:
- Google AdMob — serves banner, interstitial, rewarded, and native ads
- Liftoff Monetize (Vungle) — serves video and interactive ads
- Unity Ads — serves video and playable ads
These partners may collect device identifiers, coarse location, and usage data to serve and measure
advertisements.
2. How We Use Your Information
| Purpose |
Data Used |
| Cloud Synchronization |
Google account, reading progress, bookmarks, highlights |
| Reading Statistics |
Pages read, time spent, sessions (local only) |
| Text-to-Speech |
Book content (processed on-device) |
| Translation |
Selected text (processed on-device via ML Kit) |
| Advertising |
Device identifiers, IDFA (iOS), coarse location (via Google AdMob and mediation partners) |
3. Data Storage and Security
3.1 Local Storage
The majority of your data is stored locally on your device using encrypted SQLite databases. This includes:
- Your e-book library and reading content
- Bookmarks, highlights, and annotations
- Reading statistics and preferences
- App settings and configurations
3.2 Cloud Storage (Optional)
If you enable cloud synchronization:
- Your data is stored in your personal Google Drive account
- Data is encrypted using AES-256 encryption before upload
- We do not have access to your Google Drive; you maintain full control
- You can delete synced data at any time through Google Drive
3.3 On-Device Processing
We use Google ML Kit for translation and language detection. All ML processing happens entirely on
your device - no text is sent to external servers.
3.4 Data Transmission Security
All data transmitted to third-party services (including Google services and ad networks) is encrypted using
secure HTTPS connections. We use industry-standard encryption protocols to protect your data during
transmission.
4. Third-Party Services
| Service |
Purpose |
Data Shared |
| Google Sign-In |
Authentication |
Email, profile info |
| Google Drive API |
Cloud backup |
Encrypted app data (to your Drive) |
| Google AdMob (with Mediation) |
Advertising |
Device ID, IDFA (iOS), usage data, coarse location |
| Liftoff Monetize (Vungle) |
Ad mediation — video ads |
Device ID, IP address, usage data |
| Unity Ads |
Ad mediation — video and playable ads |
Device ID, IP address, usage data |
| Google ML Kit |
Translation (on-device) |
None (local processing) |
5. Data Sharing
We do not sell, trade, or rent your personal information. We only share data in the
following circumstances:
- With Your Consent: When you explicitly authorize sharing
- Service Providers: Google services and ad mediation partners as described above
- Legal Requirements: When required by law or to protect rights
6. Your Rights and Choices
- Access: View all your data within the app
- In-App Data Deletion: You can permanently delete all your data including books, highlights, bookmarks, reading sessions, reading goals, vocabulary, caches, and preferences directly within the app by going to Settings > Delete All Data. This action cannot be undone.
- Delete: Remove your local data by clearing app data or uninstalling
- Cloud Data: Delete synced data from your Google Drive
- Opt-out of Personalized Ads: Adjust in your device's Google settings (Android) or iOS
Settings > Privacy & Security > Tracking (iOS)
- Consent Management: You can review and update your advertising consent choices at any
time within the app's Settings > Privacy
- Sign Out: Disconnect Google account at any time
7. Children's Privacy
Libris is not directed at children under 13. We do not knowingly collect personal information from children.
If you believe a child has provided us with personal information, please contact us.
8. Changes to This Policy
We may update this Privacy Policy from time to time. We will notify you of any changes by posting the new
Privacy Policy on this page and updating the "Last Updated" date.