ScriptCat, a browser extension that can execute user scripts, everything can be scripted, allowing your browser to do more things! About We built a framework for executing background scripts and Greasemonkey/Tampermonkey scripts based on the design ideas of Greasemonkey/Tampermonkey. It also has several unique APIs that enable scripts to do more. Furthermore, we provide a fantastic online editor that makes script code development more pleasant and easy. Please Star it if you find it useful. ❤❤❤ Features

Cloud Sync: script recovery is easy when changing or reinstalling browser
Scripts subscription: creating your own script collections or enabling multiple scripts to work together.
Compatibility: allowing seamless migration from other userscript managers.
Background scripts: allowing your scripts to run continuously in the background.
Scheduled scripts: allowing for daily scheduled tasks. You can use them for automatic check-ins, timed reminders, and more.
Rich API: more powerful APIs than other managers, which can realize more functions.
Sandbox mechanism: ensuring user safety, script permissions are granted only with user consent.
Excellent editor: providing API auto-completion and ESLint.
Nice UI

...More features are Coming. Discussion

Other API Document:https://github.com/scriptscat/scriptcat/tree/master/docs Github:https://github.com/scriptscat/scriptcat

Developer response