Sorry but it just doesn't work.

First of all, the icon appeared on my toolbar and not anywhere near the YT video I'm watching, so it's not very user-friendly for someone who has already a lot of add-on icons (they DO work - thanks Firefox and developers).

Second, it opens a page that asks me to input the URL for the video. Once again, not user-friendly.

Finally, I click and get no MP3 file.

I encourage the developers to look into it, because the idea is great. Unfortunately, right now I'll have to uninstall it and look elsewhere to download MP3 files.

(PS: as a translator I do it for work: foreign language files, lessons etc.)