By far this is the best userscript manager available for Firefox and the over hyped forks based on it. It is comprehensive in its feature set and documentation, has a much easier to understand interface than the others in the settings tab and the popup window's absolute perfection ESPECIALLY because following it to find scripts for sites, it enables me to search for user scripts on the common sites quickly and easily.

Bundling in the user styles means not needing a second add on to deal with, it makes turning or off styles (and scripts) painless if some style looks nice but the site into a nuclear disaster site like some do and its got an icon that I (who has modified my browser to degrees no one else would be willing to do and have a customizable add-on toolbar on the bottom of the screen) is clear in whatever size and not over or under designed which fits nicely with my overall browser appearance.

Developer is responsive and active on Github but search if issues arise before posting issues, which if you even have a Github account you should know how to do anyway so come on.

It works

Is it possible, by any chance, at some point, to get something like uBlock's procedural cosmetic filters for our UserCSS scripts? CSS is great, but it's a bit lacking in functionality, especially in regex support.
I'm only starting to learn JS, and I imagine it's gonna take a while before I'll be able to write the scripts I need.
Thanks for all your hard work!

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The UI is much better and more intuitive than that of TemperMonkey.

I really like the distinction between CSS and JS modifications and that I don’t need to use “proprietary” GreaseMonkey functions like GM_addStyle (` /* the CSS goes here */ `).

FireMonkey also doesn’t exhibit the bug that TemperMonkey does — when I navigated the same portal over many pages, it seemed TM kept adding the same CSS script over and over, which, over time, slowed Firefox noticeably (after a while TM reported aplying about 70 scripts instead of 2!).

Perfect better than the alternatives.

It is indeed super lightweight. A nice advantage to being on Firefox, as it's not available elsewhere.