This add-on basically applies a high-contrast theme to site fonts, getting rid of the boring gray text that so many sites are filled with (which I only realized when I started using this). It works perfectly and you can easily turn it off and on for different pages. You can also whitelist or blacklist sites so that sites you visit regularly look good with no fiddling required. There are plenty of settings to mess with though if you want. On default settings it's actually pretty smart about where it applies the contrast fix--it doesn't blacken links or text that's supposed to be colorful, and it has made everything easier to read for me so far. You might think it would look janky but actually, everything looks cooler when the text has some weight and doesn't blend in with the background. It's a subtle "digital" aesthetic. Perfect add-on.