Great Concept _ but BAD creation.
1) anything above 100 % - there is a slight hum the background.

2) it doesn't "stay assigned" - Everytime i open firefox, I need to re-assign it to the level I need. .. ALL of the other extensions ... stay the way I set them - like my ad-blocker I do not "need to" ... 'turn it on' ... for every use.
I turn it on, set it & forget about it ...

this one I constantly need to "re-assign the level I had set the last time I had the browser open"

3) ( all of your keyboard shortcuts are already assigned by YOUTUBE, # keys refer to the chapter you want to watch, Arrow keys ALREADY assigned to control "move page up or down on page" , Right & Left arrows ( ALREADY assigned to move forward or Backward in video by ) 5 seconds.

4) STOP the constant need to ask questions !
( upon every use ) .. do you want to use this ad free - or pay for a premium to remove ads.

Yes - I am fine with banner ads.

Why the constant NEED to ask - if I already told you the answer.

if the extension app asks any more (stupid questions )... a questions I have already answered multiple times previously ) _ i will change my rating to a 0 star.