If your iOS app supports ProMotion but you're still seeing 60fps instead of 120Hz, this is your debugging checklist. It walks through the systematic diagnosis process: render loop configuration, frame pacing issues, system caps, and hitch mechanics. The key insight is brutally simple: ProMotion availability doesn't mean your app automatically uses it. You have to configure it correctly. Part of the larger Axiom collection (948 GitHub stars), this focuses specifically on variable refresh rate displays across iPhone, iPad Pro, and future devices. Also covers production telemetry so you can catch frame rate problems in the wild, not just during development.
npx skills add https://github.com/charleswiltgen/axiom --skill axiom-display-performance