What if learning French were a climb through the mountains?
I took French at school, but to this day I speak it very badly. I lacked the motivation and a clear learning path, so I built Rappel. The iOS app wraps learning in a small pixel RPG: every lesson is a place in the mountains, and what you secure clears the clouds over the next land.
App Store14 min read
Open a screen for the annotations.
Tools
SwiftUI
The app and its lesson flow.
SpriteKit
The walkable mountain map.
SwiftData & FSRS-6
Progress and spaced repetition.
Claude Code
Building it out.
Next project
Lernwelt Voci2026