As my User Account name says, I'm using a relativly expensive mobile data connection to browse, with limited fast internet quota. - Mozilla forgot to mention that this "RECOMMENDED" add-on wants money, and because it is "RECOMMENDED", that would "SATISFY OUT SECURITY AND PERFORMANCE STANDARDS", I didn't read the user recommendations first.
I have NOTHING against commerical software, but I want to know upfront!
There are free alternatives.

MP3 Download kostet Geld.

In full HD 1080P does not work; blocage at the end ?? My new mail is nick56@bbox.fr insteed of nick56@orange.fr

Does not let you download anything other than mp4 lowest quality... At least fucking say that you gotta make me pay to download a mp3 right on the tin rather than making me wait abit

Actually useless. The only thing you can do is 360p MP4 download. Everything else wants you to pay. You're better off using one of those sketchy Youtube to mp3/mp4 type websites

Support for Donation! Does NOT work with MP3

No descarga, solo si pagas, mala extension, no se como es recomendada.

dumpster for donations, I don't recommend it!

Nope! Youtube already lets me download up to 720 video. I wanted 1080, but when I tried to use this extension, a big error message appeared that said, "Youtube switched to separate audio/video streaming technology for higher quality formats and no longer provides direct 720p (Since 24 September 2018)/1080p/mp3 streams. Converting these streams to downloadable formats for you needs powerful server infrastructure, therefore 1080p/mp3 downloading has been limited to PRO users. Read more at - https://videodroid.org/pro_upgrade.html. FREE users can download all formats in CACHE where some PRO users fetched the video/audio in past 24 hours, to test the feature you can try downloading popular videos."

Csak szar minőségben enged letölteni ingyenesen. Megy a kukába. Nyerészkedjetek máson.

Pretty crazy they feel safe charging for this when there's still tons of websites that do the same. I'm a bit of change for that download as button.

it is amazing how the "PRO" version works still

i just installed the latest version 18.5, but unfortunately although it claims it downloads anything but 1080 KBPS-mp3, unless you uprade to the PRO version. But in reality it doesn't allow any download, even the very low 128 KBPS ones - unless I guess you upgrade (but even that isn't sure, I won't try it since their statement doesn't reflect the reality).

Deceptive, Paywall, Don't bother, just look for another alternative.

It's a spam. Avoid !!