Fast, light, intuitive, looks good. JS & CSS combined. Extremely responsive developer. Native userscripts API. Would recommend. One of my favorite extensions across any browser (Firefox, Safari, ug chromium, iCab, Orion)

+ fast & light
+ UI makes sense and doesn't require too many clicks for any given action (cough cough… ViolentMonkey)
+ responsive developer (responded within the day to multiple messages and willing to try to reproduce issue on own end)
+ well-done documentation, although it could be a little clearer for new users
+ runs both userCSS and userJS. I cannot understate how important this is. Having to run CSS through JS when using chromium is awful. Do not understand why other userscript managers (except, to my knowledge, Userscripts for Safari, another great manager) do not support this. Dealing with the lack of standardization of Stylish is not necessary, and you really shouldn't need a second extension for this anyway.
+ ability to set default templates
+ themes & extensive CSS & syntax options
+ native Firefox userscripts API

− some odd UI choices
• script-related buttons only visible when the "script" context is selected. This means you cannot directly create a new script when opening settings unless first you choose a script from the sidebar or the "Script & CSS" button in the top toolbar
• the location of the toggle button makes it look like you're enabling/disabling the individual script you are viewing, even if multiple are chosen
• other small confusing behaviors like this, almost all related to the choice to place almost all of the action buttons in the script context view. Not really confusing if actually working in the settings, but was confusing at first due to trying to open and create a script, but buttons not available. This is the main reason for 4 stars, but it is a single developer and I'm sure they would be open to feedback in this situation.
− slow and somewhat unsatisfying save animation, but it may be necessary, given I've had issues in the past when saving and continuing with other actions too quickly. Unsure if this is FireMonkey- or Firefox-related.
− Extension seemingly chooses at random whether or not a script is enabled when importing; although whatever logic is being used actually does seem to somehow choose accurately most of the time, and it's usually defaulting to enabled

Seems like we can't import scripts from zip
Right, unzip everything and import works, but slightly inconvenient, thank you for replying.

I am looking for an alternative to Tampermonkey. FireMonkey looks promising. However, it does not support importing a .zip created by other managers. Therefore, I use Violentmonkey instead.

I've read https://github.com/erosman/support/issues/236

This addon is nice, it's pretty simple to write js scripts with it, however I've struggled to write css scripts. I would assume that it shouldn't be too different from normal css, but trying to port my css scripts from stylus to firemonkey hasn't worked. There might be something simple I'm missing but I haven't been able to figure out what it is. I think the css documentation could be improved to make it easier to write css scripts.

É uma extensão muito boa para se utilizar tanto na Área de trabalho quanto no Firefox para Android, só não estar funcionando a exportação das configurações da extensão e tradução, quando utilizado no Android.
Somente a importação das configurações funciona no momento.

Great to see a lightweight unified userscript and userstyle manager, however one major complaint is missing CSS preprocessor(whatever stylus supports) for usercsses, please consider adding!

wish the css part was as intuitive as Stylus

How to "adapt" a script for this addon? I installed one script from greasyfork.org to download music from VK. It doesn't work and doesn't show any error messages. (Works fine in Greasemonkey).
I know that addon itself has nothing to do with that particular script, but since it links to greasyfork, I expected to have somewhat compatibility with those scripts.

Maybe there is a setting to allow script to download files? IDK. I thought so but couldn't find..
--
UPD: thanks for response! Do you mean I should create an issue on github? That script btw: https://greasyfork.org/en/scripts/38614-vk-media-downloader/code

Hello, is it possible to install user script and style from userstyles.org?

Very nice idea. But it doesn't allow you to install scripts or styles from the main repositories (like greasyfork.org or userstyles.org.) You would have to add them manually by copying and pasting the scripts' text I guess.

I tried importing my scripts from greasemonkey gsm folder but the one I tried (google hit hider) just returned an error.

Also don't know if it supports v4 greasemonkey scripts along with v3?

Looking forward to trying this out when these things are working.