Cross-Platform Golf Swing Analyzer

I want an app that helps golfers record and analyse their swing on both iOS and Android phones. The core of the project is accurate, frame-by-frame swing analysis: the user opens the camera inside the app, captures a swing, and then sees clear visual feedback—slow-motion playback, key angles highlighted, and comparison with previous swings stored locally on the device. A clean, intuitive interface is important; users should reach the analysis screen in as few taps as possible and scrub through the video smoothly.

I am open to whichever stack you feel delivers the best real-time performance—native Swift/Kotlin, Flutter, or React Native with the right camera and computer-vision libraries—but please outline your choice and why it suits this specific task. If you have an off-the-shelf analytics engine or a custom model ready to integrate, even better; otherwise, describe the approach you would use to detect club path and body positions reliably.

Deliverables
• Production-ready iOS and Android builds
• Full, well-commented source code
• Short setup & maintenance guide so I can run future builds myself

Please include a brief note on similar video-analysis or sports-tracking projects you have shipped and the libraries or frameworks you used. I will shortlist based on proven experience with high-performance camera apps and clear, maintainable code.