I first tried this Add-On on my Opera Browser! Wow! Incredibly fast and simple w just one click! But if resolution is not allowed on your monitor, you have to choose from the menu beside the Green Arrow below the video you will be downloading. Then, downloading meters will appear on the top right corner of the browser.

Klasss

es la mejor, lejos. la unica que funciona y es simple.

Awesome addon, save my day by downloading complete youtube playlist in couple of Clicks.... Truly Awesome. I used this since last 3 years

If you want to download anyting in 720 or 1080p it requires you to download some other program to your PC. It should have be written in the major description, I don't like this kind of clickbait.