Nice and easy to use, but honestly what I need most is some kind of sharpness filter.
Just got a 4k screen, and it's really made watching 1080p content on youtube a worse experience.
The perfect thing would be an integer option that could upscale 1080p to 4k, but don't know if that's even possible, or maybe a way to make the Nvidia edge enhancment work in Firefox, since it doesn't currently and hasn't for years.
Would be nice if the extension had the option for choosing what sites to work on, maybe with the possibility for different settings for each site.
Oh, and have the settings work in 1% steps rather than 10% for better adjustments.
Just my 0.02 regarding possible improvements. :-)