Open source and works great.

查找網站腳本最好用的猴

应该是最好用的开源脚本管理器了，感谢开发者为我们带来这么优秀的扩展！

It stopped working in firefox android nightly

This is the superior userscript manager. It's free & open source, it works perfectly, and has frequent updates. Goodbye tampermonkey, rip Greasemonkey (hasn't worked right in years).

A great, modern alternative to Greasemonkey, also in terms of the supported API. And it's open source (unlike Tampermonkey), which I consider pretty important for an extension that can access and modify every page you visit!