Audiobooks are great, but plain listening is passive. Your mind drifts, you miss a key sentence, and you end up rewinding to find where you lost focus.
I wanted something better: synchronized, word-level text you can read while you listen. Think Apple Music lyrics, but for books.
So I built HushBook — an accessibility-first, privacy-first audiobook player that turns any audiobook file into a word-by-word karaoke experience, transcribing everything directly on your phone.
Click the image above to visit the live site at hushbook.app.
What it does
HushBook highlights each word in real time at up to 60 fps. As the narrator speaks, the active word lights up and the page auto-scrolls. If you want to jump to a specific part, you just tap any word to seek the audio directly to that moment.
Everything runs entirely on your device. There are no accounts, no cloud uploads, and it works completely offline.
The On-Device AI Engine
Most transcription apps send your audio to a server. That's slow, expensive, and a privacy nightmare.
HushBook solves this by running whisper.tss natively on the phone via Dart FFI.
- 100% On-Device: Transcription runs locally on a SQLite database. Your books never leave your phone.
- Offline First: After a one-time download of the AI model (Tiny to Medium sizes), it requires no internet connection.
- Resource Aware: The engine caps worker threads and idles between chapters to keep the device cool and save battery.
- Resume on Failure: It transcribes long books in chunks. If the app is closed, it resumes exactly where it left off.
Built for Accessibility
Reading is not one-size-fits-all. HushBook reshapes its UI based on three custom reading profiles:
- ADHD & Dyslexia Mode: Uses the OpenDyslexic font, a reading ruler overlay, and adjustable line-spacing to anchor the eyes.
- Low-Vision Mode: Uses the Atkinson Hyperlegible font, extra-large captions, and high-contrast color themes.
- Comprehension Mode: Adds checkpoint questions and tracks active focus metrics to help you retain what you read.
Thousands of Classics + Your Own Files
You can browse and download thousands of public-domain titles from LibriVox and the Internet Archive directly inside the app.
Have your own files? You can import:
- Audio Formats: MP3, M4A, M4B, AAC, FLAC, WAV, and OPUS.
- Smart Metadata: Auto-detects M4B chapter markers, covers, and metadata.
- Fingerprint Recovery: Uses audio hashing so if you re-import a deleted book, you restore your progress and transcripts.
Habits and Insights
HushBook Pro adds on-device analytics to track your reading habits:
- An annual reading heatmap and 10-genre radar chart.
- Daily word goals and attention curve tracking.
- Interactive character relationship graphs mapped on a visual canvas.