It stopped working and the developer moved to a desktop version. Someone reported that the developer is still taking money for the extension. Should be removed and NOT be a recommended Mozilla add-on. Was very good back when it worked.

The add-on is FREE to download, but as soon as you try to actually use it, it tells you you need to BUY the PRO VERSION!!!

I've been using this for years as a pro user! It is awesome. Come on guys it's only 30 once! There's no annual fee like so many programs nowadays!

Wants you to pay to actually use the addon now. Don't bother.

Works just about fine.

no veo nada youtube

Normal youtube download websites recently started only offering 360p versions of their videos with sound, or 1080p versions with no sound, so I looked up a better way to get full video + sound... and this is it! I tentatively upgraded to pro and it has worked perfectly. Thanks for dealing with Youtube's nonsense for us!
Update from a year after I started using it: still going strong! This extension is awesome!

Excellent performance. Doing great job.

the greatest downloader. nothing else is remotely close.

spend a few bucks years ago and best yt downloader in the net.