Home | The Scrutinizer - 171 things you can do to your URL
This is a browser extension called "Make the web yours" that lets you customize any website by writing JavaScript or CSS snippets called "Recipes," which can be triggered automatically based on URLs or run manually via keyboard shortcuts. The tool works offline, syncs across devices, exports as bookmarklets, and emphasizes privacy by storing all data locally with no tracking. It's open-source, accessible, and designed as a "Zero Data app" where you fully own your customizations.