StoryRuler is a lightweight macOS overlay for video editors. It sits above Premiere Pro, DaVinci Resolve, Final Cut Pro, or any other editor, and shows a visual story structure guide directly over your timeline. No plugins. No setup. Just a transparent ruler that helps you see pacing, structure, and key story beats while you cut. Built-in templates include Three-Act Structure and Save the Cat! Beat Sheet, with support for custom markers and structures.