Nonsense, absolutely.
if you have only one video on the page, for example 5 MB of size, the extension shows you at least 5 non-working links with size of 1024 KB (all links are the same), couple of links with correct size and name, but they don't work, and finally one working link, but with auto-generated numeric name. And it's 50% chance that download will not be finished.
The same time i tried 2 other extensions, and the work as should exactly on same pages.

Wondershare's Video Downloader does a far better job in much less time and with much less hassle.

Watermark for download video? Are you serious?

Converting a video often stops or it never ends. This results in an insanely high CPU load! All fans turn at full speed. I strongly recommend that addon not to install.

I suggest to use jdownloader2 instead (It's an app not an addon).

I am hating this application. It doesn't work. The video I try downloading says "Aggregating..." but never stops. This means that the videos never truly download. It just sits there. Am I supposed to download something else along with it? If so then this program is ridiculous. I am looking for something else.

Suddenly requires a companion app to do anything else (installing software on PC) I've uninstalled it.

Insère de la pub dans les vidéos, option payante pour retirer. Poubelle.

This add-on worked fine for free before, now it has a giant watermark on any video.

Hot garbage. does nothing special that other video downloaders don't do, and requires an add on to convert video to other formats that immediately asks for money to convert. Probably paid for the good reviews. Avoid.

Firefox recommends the addon. I add it to my browser. I want to download a song ... I am automatically linked to a page and have to download another program to my PC. I think it's a virus, I'm deleting the addon.

But hey, this is Firefox and Firefox recommended the addon - it cannot be a virus. I read the FAQ on the developer side, they look honest. I download the addon again, I download the "program". I want to download a song and convert it to MP3. I am redirected to a page and have to buy a license that costs 19 euros. I am considering buying a license, but I do not get an answer as to how long the license is valid. Okay, I still want to pay. I cannot transfer money because only VISA, Mastercard, American Express are accepted.

Why don't you write this information in the addon description? Look up the term "transparency". What you are doing is a jungle of links and redirects!

It's paid now, what isn't clear when you install.

Non-functional on Firefox in 2020. Asks for Companion App, but till doesn't work after installing it.

You have to install an extra 'companion app' from another source. Very suspicious...

requires to download compagnion app

Данное дополнение позиционирует себя как загрузчик видео с сайтов, однако оно является лишь ссылкой на скачивание внешнего приложения.

This add-on positions itself as a video downloader from sites, however it is only a link to downloading an external application.

The extension leaves a watermark on all the videos unless you pay.