Caffeine was the old application that Amphetamine replaced. It was a long-standing utility that went unmaintained after Apple switched to the retina displays.
Really? I am still using it. It works fine with a Retina display, which is the only Apple display I've ever had.
2014 MBP 15 here.
There is already an app called "Caffeine" that serves the same purpose.
I just did a search and found multiple apps with that name already.