The night shift mode on this blog has got to be the most pointless I've seen. Black text on black background with a reveal effect when you move your mouse!
"Please don't complain about tangential annoyances—things like article or website formats, name collisions, or back-button breakage. They're too common to be interesting."
Simple implementation too, the light is actually the background and that is offset in response to mouse events, I've seen similar effects done in horrendously overcomplicated ways that don't work nearly as well due to z-order issues and such. Credit to the creator.
https://news.ycombinator.com/newsguidelines.html