The extension description promises downloading audio (MP3) but it's not part of the extension and needs to be paid for.
I have not tested anything else but it migh work.

Does not make it clear enough that 1080p downloads require paid upgrade.

Plugin works (limited functionality without a pro account though).
Not being able to download 1080p without a pro account is a pain, but saying powerful server infrastructure is needed to convert 1080p video is utter bullshit. Pick up your game dev.
Will not be using this plugin, it is useless to me, as I'm not paying a pro account.

I have tried a few different video / audio down loaders. Yet I keep coming back to this one. So far I like this one best because it's the most user friendly and convenient. Great for those that want a fast, basic, trouble-free solution. You get 2 levels of quality for MP3's & MP4's and you can direct where you wish to locate your downloads. For example simply choose your desktop, pictures, downloads file, etc.I normally use desktop and watch later right there, or store it on a flash drive for my TV. I am not nearly as particular about how sharp and HD the picture quality is for my You-Tube videos as I would be for real movies & TV shows I want to save longer or watch more than 1 more time.

NO BAIXA MP3 POR QUE LIXO... ERA PRA QUALIDADE DE ÁUDIO 128KBPS OU 320KBPS DONLOAD GRATUITO NO PAGA AFS QUE MERDA ESSA...

Why don't you just make a sign in page when the browser loses you

Anuncian que puedes descargar mp3 y resulta que hay que pagar. Un engaño.

Gold digger. Can't convert the audio to MP3 without paying. Better off with another add ons.

I can't download Full HD.

MP3 und HD geht nur nach Donation, 10$ Minimum.

UPDATE 3/06/20: It was one of my Best video downloaders. But You must pay to download the Highest quality video on the list. Even if the 720p is the highest, you can not download it. Recently I discovered other FREE online websites that can download 1080 full-HD or higher resolution videos! Such as: (https://ddownr.com/) and (https://loader.to/) and a software (https://televzr.com/) . So I have to removed it from my Addons to release space on my browser.
If you make this addon free again to download 1080, I will install it again. Thanks.

does not allow to download at full quality.

1080p and 256 mp3 only with PRO versions...goodbye

The developer responds quickly to bug reports in reviews, although he complains that users "jump quickly" to post negative reviews "as soon as a bug appears."

Well, how would a new user know that a bug just appeared? Furthermore, the developer's support page says that the support system is shut off, except for paying "pro" customers. That leaves reviews as our only means of communicating problems.

And there are still problems. The developer quickly fixed an issue where the "download as" buttons did nothing (referred to in the "fixed" message below)... but the plug-in still does not appear to work. I did in fact upgrade to the "pro" version so I could download 1080p material, but an attempt to do so simply evokes a "dispatched for processing" message. After 45 minutes, I still have no sign of the video being downloaded.

The publisher's user forum ( https://youtube-downloader.uservoice.com/forums/225282-general ) is useless. It lets you type out an entire question (or "idea") but the "Post idea" button does nothing. Don't waste your time.

Large message blocks corner of video and is not dismissible. "Support options" are non-existant for non-paying users.

1080 downloading, not working

Can't download at highest resolution (ex, If the video has 480p and 360p you can download at 360p only.

It's "Free" as in "Please pay for a PRO upgrade if you want your videos in actual 1080 HD, thanks".

What a waste of time.