Greasy Fork is available in English.
Convert to mp3 from Youtube clip, if you want to open in background tab - middle click.
Okay noted...
I'v not tried in greasemonkey / FF,
i'm updating this script with a new version with different/ multiple choice of converters, then i'll try to make it compatible
/magnus
Download error when I try to install the script.
I'm using Firefox Greasemonkey, and I can't use this script. Something about the match rules.