It puts a giant QR code in your video.

The extension watermarks downloaded videos

"Kernel-Power 41"が頻発している理由がこいつでした。
電源やハードウェアを疑い新しいPCでもこのエラーが続くので怪しいと思いこのアドオンオフにしたところ一発解決。今現在何週も安定動作しています。
他のブラウザやFirefoxを放置した状態でPCの強制シャットダウンが頻発してたのでしかもアドオンなので盲点でした。
恐らくメモリにかなり負担をかけているのだと思います。ブラウザ全体の動作が遅くプチフリーズのような症状も大体こいつです。
もしこの症状に悩まされている方は試す価値はあります。

The companion app does not work on Linux, making this nearly useless.

Requires the additional download and installation of a program on the computer, and then, only after installing that and downloading a video, does it inform you that it watermarks the videos, neither of which are mentioned in the info about the extension. Finally, the app is semi-obscurely named "VdhCoApp" as a final insult, making it harder to find to remove. Just use TarTube and forget this garbage.

Doesn't work with WhatsApp web

WHAT A MORONICALLY DUMB INTERFACE!!! IT IS ALMOST IMPOSSIBLE TO FIGURE OUT WHICH RESOLUTION TO DOWNLOAD FROM THE STUPID LIST PRESENTED. ONCE DOWNLOAD STARTS, THIS MORONIC EXTENSION RENAMES THE LIST OF STREAMS, THEN YOU HAVE NO IDEA WHAT THE HELL IS DOWNLOADING, AND HOW TO DOWNLOAD AGAIN. DROPS STREAMS ALL THE TIME TOO, AND SOMETIMES MAKES CORRUPTED VIDEO FILES. I MEAN IT WORKS, BUT WHAT MORON THOUGHT OF THE INTERFACE??? ALSO PLENTY OF SETTINGS ARE GIVEN, WHICH ARE EQUALLY MORONIC AND DIFFICULT TO COMPREHEND. HOW HARD IS IT TO MAKE AN INTUITIVE INTERFACE??????????????

Asks for installing aditional Software beyond the add-on, avoid this scam.

Doesn't work on youtube

False advertising.

This add-on makes all your videos have a QR code in the corner advertising its paid version. This would be OK - if it were transparently advertised like this on this add-on page. It is not, and you only are made aware of it after using it. This is dishonest and wastes your time.

dont recomeddd.... I using this addon a few years ago, this was free but now for any DOWNLOADN this addon NEED YOUR MONEY, DONT DOWNLOAD, DONT WASTE YOUR TIME. in firefox addons its a lot of better allternativ, DONT WASTE TIME FOR this WEAK addon

DOes not work

I didn't like it. When I tried to download a video available, it asked me to install additional software,....

Maybe warn users about the QR code watermark BEFORE making them wait an hour and a half to download and aggregate a fifteen minute video?

Absolutely useless video produced after waiting an entire day for it to be processed, because a watermark is left in the corner of the video. Don't waste your time!

I even bother to create an account to give this extension 1-star rating. This extension is full of bs. It asks you to install a shady exe companion and add obstructive QR to any video you download except you pay them money. Total garbage freemium which should be mentioned in the first place in page.