This add-on is an additional search in the universal search bar. Upon looking for a song, I was directed to a page which will stream the song in question. Clicking on the name of the song directed me to another page that had a video and an icon that appeared to be for downloading. Once I clicked that, a page full of text loaded, and I was left with no download. I can't tell you what the page said, as I do not understand what appeared to be French, which is the site's language.
There is no actual download to my knowledge, and this add-on is pointless. Unless, of course, you need yet another site to stream music from.