Simply the best dark theme provider - tried many others for individual sites but this one works for all sites and works great.

Edit: Some issues; it inverts gifs and other things on twitter so you're better off disabling it for twitter and using twitter's native dark theme

One or two other sites don't get along but you can turn it off for a second on those.

Would be nice to have a list of sites it's "on" for and "off" for.