Best video downloader I've used, but not quite free anymore.
I've used this for a few years to download videos that no other add-on could grab. when they added the companion app, configuring it got a little confusing. now the free version smacks a QR code in a corner of the videos you download. I understand that developers need to pay bills, but free to $30 is kind of a big jump in price.
it's definitely worth it, but pricey.