When a book becomes a place.
Extrapage publishes children’s books that don’t end at the last page. For Arthur & Eugénie, we built a companion app: read the printed volume, then continue the investigation in a 3D-reconstructed pyramid.
The challenge: stay faithful to the writing (text, tone, pace), without turning the app into a chatty videogame. The tablet had to feel like manuscript, sand, torches — not the app store.
We worked 9 months with the author and illustrator in tight back-and-forth. All content was written for the tablet, not ported from the book — the only way the touch gesture makes sense.
IntentNo gamification.
Just augmented reading.
- No score, no timer, no cheap dopamine. The child takes their time.
- Each interaction is a reading gesture: turn a page, lift a veil, decipher a cartouche.
- Audio is central — optional voice-over for early readers, discreet sound design for atmosphere.
- The app works fully offline. Designed for long trips, not push notifications.
A sober stack, built to last.
Unity for real-time 3D (pyramids, manipulable objects), with a thin native wrapper for reading state and progress. Text and audio content is local-first — no server, no tracking, no subscription.
Everything ships as a native build — iOS and Android — calibrated to run on 2018 iPads and Android tablets and up. Not the latest, the most accessible.
Performance
Target 60 fps on a 2018 iPad, minimum 30 fps guaranteed on mid-range Android. Total memory < 380 MB. Everything fits in cache.
Accessibility
Full voice-over, synced subtitles, AA contrast, dyslexia mode (OpenDyslexic optional). No timed tasks imposed.