Unbelievable that there is a recommended by firefox add on that doesn't work on its own and ask you to download something outside of the add on pages...
Simple put it doesn't work and ask you to download something else, suspicious at best.

Très facile à installer, très simple d'utilisation. Permet de récupérer un grand nombre de média sur internet.

SAYS IT NEEDS "COMPANION APP" TO RUN BUT DOES NOT DOWNLOAD/ACCESS THAT EXT!

Pas d'icône du module dans la barre Firefox.

Easy to use, works reliably, would thoroughly recommend it

simple et efficace

The best program for easy quick and high quality video downloading from all sourses. I recomend it for all users. It works great!

Very easy to use. Works well.

I like some videos, but I can't download them. At this point, I found someone on the Internet recommended DownloadHelper. Thanks, this component really helped me solve my problem，Thanks to the developers, it's easy, easy, and fast. I really can't find words to express how much I love this component，thank you very much all developers.

It sometimes works for me on most websites (except youtube) .
Very unreliable, specially for slow connections. Suddenly crashes or claims download is finished (but it's not).
You need to check every video manually if it has fully, not corrupted downloaded. Re-starting downloads of such vids is a PITA, sometimes it just don't.
Regarding the "companion app": I can see in the ressource monitor that this app does not send data, it only receives. Means: I didn't catch it spying.

aunque a veces tenga algunos pequeños fallos, estoy muy contento con el uso de este complemento. Va de maravilla, es rápido y la mayoría de veces descarga con una alta definición.

I'm using this add-on for well over a decade, but it hasn't been working on most websites for well over a year now. I never paid much attention to it and assumed it'll be fixed sooner or later. But I guess not. I'm removing this add-on now with a heavy heart. Time to find an alternative.

这个下载视频不错啊。很快的

ottima