It WAS an excellent addon for downloading every video and playing it off-line (especially helpful with slow or unstable Internet connection). Nevertheless, now it doesn't work with Youtube.
I'm not sure about version with functionality broken - I haven't updated it for a while. Anyway, it doesn't work now.

I have a very long history (several years) of working with Video DownloadHelper (VDH). In the beginning, it was the perfect app for me to use to download pretty much any video I wanted to, and in some cases converting a video to audio.

I have noticed an increasing number of videos that require an external app loaded to complete the conversion that used to be handled solely by the VDH. I don't feel comfortable installing more apps on my computer that I don't know just on someone's say so. As a result I'm unable to use VDH for most of my needs.

ok

Does not always work

While it works, there are times when it seems like it has worked properly only to save a file that is just a big green block and no video or audio. If not for that, I would have given it a 5 star...

Payware.
Free version NOT usable to download videos. But o.k. to get the audio part (can be converted externally).

I liked it better before it was "improved." When saving a stream, there are too many choices even when there is only one apparent stream on the page. The old interface was simpler and I liked it better.

Before payment became mandatory, I used VDH fairly often. Afterwords, I just did without. So I have no idea how well the program works. The free version was very slow at processing the data into MP4 format.

tu devrais le mettre encore plus gros le QR code ca donne trop envie de payer de cette facon (ironie) sinon j'aurais mis 5 étoile

The new update seems to have broken a lot more video downloads. Used to have only the odd very obscure player not work, now it is on a regular basis and ones that used to work that were less popular no longer do.

Unfortunate, but for most use cases, you'll probably be fine, however, there are other tools that can fill this need if you look around Github.