I just happened to stumble on this one: an online writing app called Writer. The interface is a black screen with fluorescent green text. It’s like typing on the computer that Matthew Broderick’s character used to access the defense system computer in WAR GAMES. I’m old, so I remember the “dumb terminal” computers we used in the eighties. Staring at that color combination made for bleary eyes at the end of the day.
I reckon the advantage of using this system would be for sudden inspiration and all you have is your smart phone or tablet without your word processing software. I just can’t imagine spending hours writing on an interface like that. It seems like a kind of hipster novelty to me.