ChinCheck
The idea: point your phone at yourself, shadowbox for 30 seconds, and get judged like a real fight — a score out of 100, a tier ranking, and an AI judge's note calling out your biggest weakness.
What it took to build:
- Native camera pipeline with on-device pose tracking (Swift on iOS, Kotlin with ML Kit on Android) feeding a JavaScript overlay in real time
- AI video analysis with sub-30-second turnaround from recording to verdict
- Live head-to-head duels over peer-to-peer WebRTC video, with screen-recorded replays
- Global leaderboards, weekly rivals, bot challenges, and a full retention system
- Complete subscription business: free trials, A/B-tested paywalls, win-back offers, and analytics on every funnel step
- Localized into 12+ languages; store screenshots and listings per market