Inertia - Keyframe animation for the UI you already built

Show HN: Inertia – Not your Grandfathers animation editor

Inertia is a macOS editor that brings keyframe animation to real, live UI components in SwiftUI, Jetpack Compose, and React. Instead of exporting video or maintaining a parallel design file, you tag views with an ID, run your app inside the editor, and drag them on a timeline to create animations. The editor writes a single .inertia file that plays natively on all three runtimes, with features like alignment guides, vertex shapes, and shared playhead. It's a seamless bridge between design tools and code-first libraries, letting you animate the actual views in your app without rebuild loops.