Some times it works, but most of the time it does not.
I'll be watching a YouTube video I like, and I'll click on the greendownload arrow in my menu bar.
It will show me a list of videos It can download.
Sometimes the previous video I watched is listed. Sometimes the video I'm watching will show up.
There will often, but not always, be a green ovoid. In that Ovoid, it will say Download 0MB.
Whenever it says 0MB, that means it will act like it's downloading something, but when I open the folder, there's either nothing there, or a file with a size of 0.
I've already paid the $15 bucks or so for the professional version.
What a rip!

Sometimes, about 20% of the time, I do see something I can download, so I'll give it some stars.
But I need to find something that is reliable.
And I see no way to convert to mp3, which is why I wanted this.