BookWalker

Lead mobile developer at M12-Media, 2024 - now

Screenshots from the App Store listing.

Readers

The comic reader is my own engine. It handles single pages, two-page spreads and vertical webtoon scrolling, where wide spread pages can also be scrolled horizontally inside the vertical feed (see the demo). It keeps the exact reading position when you switch modes or rotate the device. The same mechanism opens a comic at a precise location. Pages are DRM-protected and decrypted by native code in a pool of isolates, so scrolling stays smooth.

Light novels run on Readium, which I integrated natively on iOS and Android and bridged to Flutter over platform channels and Protobuf, with LCP DRM. Audiobooks play in the background with lock screen controls and casting. All three readers are standalone packages without UI of their own, so another app can reuse them with its own design.

Offline and reliability

Users can download their purchases and read or listen with no connection; the app even starts offline. Downloads, payments, progress sync and analytics go through a persistent task orchestrator with retries and backoff, so they finish even if the app is killed halfway.

Everything else

I also built the server-driven home screen, multi-factor sign-in with SSO and passkeys, purchases and gifting, and accessibility support: text scaling, high-contrast themes and full keyboard navigation. I brought unit, widget and golden tests to the team and set up the CI/CD that builds, tests and distributes the apps.

Stack

Flutter, Dart, Swift, Kotlin, Readium, Protobuf, SQLite (Drift), Fastlane.