This add-on is perfect, and works great 99.8% of the time. The other 0.2% is when Youtube is changing their coding and it can take several days for the add-on writer (dishita) to update his code to match.
THERE IS SO MUCH B.S. WRITTEN ABOUT THIS ADD-ON. THIS IS HOW IT WORKS:

FREE users - add it on and you can download medium mp4's and most 720 mp4's.

PAID users - You can download all 720's and any 1080's if they are there. It's these DL's that make use of his server, and he has to pay for that himself. That's why we donate.
ANYONE who is having trouble can email him directly and he responds quickly ALWAYS. Enjoy!

I love this! Just the other day someone or reddit noticed when a youtube vid is taken down you don't even know what it is your playlist has lost. Its so great to keep stuff you like permanently on your hd!

Good App will recommend for downloading videos you like, donated for the awesome work and now it's even better, 07/08/2019

very happy with this addon thanks so much!!

can Download in both Mp3 and Mp4

its so good

To be very frank, the people down voting this app are dumb af. I have downloaded YouTube videos in the past and it was super easy but lately it has been getting harder and harder for OBVIOUS reasons!!! I tried a number of apps and had a very frustrating experience. This app is 99% effective as far as I can tell and I have no complaints. Rarely it will fail to find a high quality file ( likely due to only old source file at lower quality available). I will be back to donate again if the service remains this good.
V impressed!

I have tried every single youtube downloader addon (wasted hours) and this is the only that works easily, well, and consistently. If you need higher quality >320 and 96kbps audio (which I do) just pay him the small $ fee and get that feature. Well worth it!

So easy to use and just works flawlessy

As of the first of August 2019 THIS WORKS. Thank god. It's simple and fast.

It works, unlike all of the other video dl programs.

Very nice and great thanks

جيّد جدا، شكرا

Vielen Dank für das tolle Add-On. Es funktioniert einwandfrei. -- Thank you for the great add-on. It works fine. 2019-07-31.

Fantastic add -on A++, the one man who set this up does a great job of debugging it when YouTube alters there format.