First it was for free, than I was asked to donate for this really good working tool.
I was forced, because it didn´t worked further on. But I saw that it was worth to do so - I donated 10 USD. Really not much.
But:
I was so upset, that I couldn´t find it freed immediatly and was not able to look clear, nearly hysterically I wrote to the contact for help. It didn´t last 3 hours and I got a personal answer - that´s what I call a good service.
The solution was already there, if I had stayed cool, I would have found it in the first time:

everything works very fine!!!!!

Works fine. Easy to use.

Great extension ! Takes few seconds to download a Youtube video in mp4, where Video DownloadHelper takes minutes to finally ask for money to convert...

Fantastic app, thanks for the time and expertise you have spent developing it for all of us!
I "bought you a coffee". Cheers, Chris

Excellent add-on, regularly updated and very easy to use. I enjoyed it for years!

The app is easy to use and it works (some little bugs but no big issue).

Recently, i having problem not been able to download some video in youtube. Mostly i download music video at [mp4 360p].
When i wanted to click download button, it sent me to blank white page and it did not show how much (MB). please fix it, i have been use this so long.
Sometime i did not have any choice but to use ytmp3.cc and it work, but i prefer using this add-on, so please fix it.

This works great if you don't have capable internet or have only a few gigs data via wireless.

you can quickly download great vids --->while visiting friends or family with better internet, without having to watch the whole video allowing you to visit and do things as vids download.

save the vids for a rainy day too and watch them as you can at your home even if you have no home internet.

if you have great internet better yet!,.. download vids you need quickly to use when you have more time.. thumb drive vids to laptops and get the diy projects done easier or learn about things at your own pace not tying up a family computer. Its an awesome tool. A+

This add-on has (mostly) exceeded my expectations. Highly recommended!

amazing smash.....

Happy evening! Congratulations! You're the best. Thanks. Namastê!

Excellent piece of software. Would recommend this to anyone needing a plug-in to download youtube content for teaching and research.

great addon

Pas de bouton.....

While yes, we can download videos, we cannot download mp3.

very usefull addon

Nice add-on, easy to use. Choose your quality and integrates very well with FF.

Very convenient add-on. Does what it should. No problems found.

Works good. Easy Download of useful Formats and Resolutions.

It never works for me, there is always a limitation or a note or an explanation of how something doesn't work, then it leads you to download other things externally to firefox of dubious origins.
I just want an extension to click, install and use.
This extension doesn't work like that, also they ask money.