You cannot do anything with this plugin without installing a third party app.
There are a lot more plugins that can help you download videos without the need of installing another software.

Arbeitet nicht

Giant QR code for a license website for 1/4 of the screen covers the downloaded content. Some idiot came up with it.

This is not an extension, it requires you to download and install it's own separate program on your device.

There are much better programs to download videos if you are going to install an entire program outside the browser.

Interfaz extraña y difícil de usar, y pide que descargues una aplicación extra para usarlo

Difficilement croyable 15893 utilisateurs x 5, on y comprend rien à cette app et en + il faut payer par ruse

Takes 3 hours to "aggregate" a 1 hour 1080p video at 100% CPU. The added huge QR code is really ridiculous.
Low quality, most likely due to a bad re-encode to add the crazy QR code. Don't use this. There are many better HD download addons. I've just used another one; it downloaded the same file much faster and it didn't need any encode time after the download!

Excesivamente lento. Sé que la versión gratuita tiene que recodificar el vídeo para añadir la marca de agua pero.... ¿más de 2 horas para ensamblar un vídeo de 2 minutos? Venga ya....

Doesn't working, downloading mp3 from YT as 5kb mp3 xDDDDDD

cet outil demande assez rapidement de payer 18 euros. Et uniquement par carte bleue, il dit ne plus accepter. C'est suspect et pas éthique:il devrait l'annoncer tout de suite dès qu'on voit sa description dans le site Web de mozilla.

Doesn't download Facebook videos, despite claiming to be able to. It'll download them as a series of JPGs but not as actual videos.

Requires a separate .exe application to download. Not recommended

This extension along with every other download extension I've used stopped working on YouTube this week. Be happy to send developer the error text I get.

Because you can't properly use it without a download companion from downloadHelper you don't need this AddOn.

il faut ceci puis cela et finalement payer pour convertir. Triste méthode. Quel temps perdu!

Downloads the M3SU, then downloads the entire video contents, then displays error "MP2T - No data received" which is a bs, checked that with Process Monitor, data gets received.

shit quality with watermark

Only one star because Video DownloadHelper Companion is not working. Unistall add-on.

Завантажує музику, але не відео (з YouTube та Twitter принаймні відео не завантажує). Пише, що відсутній доступ або файл пошкоджено. В принципі прикольна штука була би, якщо б усе працювало належним чином.

you have to pay EUR20 to remove a QR code watermark from videos

Ne fait pas le boulot
Aucune souplesse
Ne sert à rien à part te bouffer de la ressource
Je déconseille vivement