Full book backup
EPUB files upload to Firebase Storage with checksum validation, so your library is safe even if a device is lost.
Why readers switch
Fast, focused reading with resilient sync.
Everything you mark—notes, bookmarks, and progress—stays with the book, wherever you read.
Progress & bookmarks
Per-page progress and bookmarks sync through Firestore. Open a book on any device and continue exactly where you stopped.
AI-linked notes
Generate AI explanations tied to the precise passage. Notes sync and stay searchable by book and keyword.
E-ink tuned
Reduced motion, adjustable font weight/size, and Boox-specific refresh controls to keep pages crisp on e-ink.
Secure by default
Per-user Firestore rules, upload-size guards, and SHA-256 checks. Local data stays private to your account.
Open & portable
Runs on standard EPUB; no vendor lock-in. Export notes, and configure your own backend URLs if needed.
How it works
Resilient sync pipeline
- Book files: On first open, the EPUB uploads to Firebase Storage with checksum metadata; repeated opens reuse the stored copy if unchanged.
- Progress: Locator JSON cached locally and mirrored to Firestore for instant resume on any device.
- Bookmarks & notes: Stored locally for offline, then pushed to Firestore; pulls on demand to keep devices aligned.
Privacy stance
Your library and notes are scoped to your Firebase user. No sharing or public listings—just your data on your devices.
Per-user rules
Checksum uploads
Offline-first
Get started
Install and sync in minutes
- Install from Google Play (or sideload the latest APK).
- Sign in with your account to enable Firestore and Storage sync.
- Open an EPUB and start reading—your progress and files back up automatically.