Imagine being a web developer and not understanding a simple UI interface.... no seriously this app is simply designer to setup the best screen lighting for any time of the day. Just explore a little bit the interface and u'll find some interesting things. Wanna work late? there is special profile for it. Night worker? you can revert the night/day profile in the options. And also you DO NOT NEED custom profiles. That's simply useless because having a full time yellow screen isn't that good since the main advantage of screen is displaying blue colour; a colour which make the person more awakened that can be as good in day for concentration as bad for sleeping at night. So stop crying and just use this awesome application. And for circadian response you can google a little and get as much information as needed to understand the UI. Ps: Are you a Mac user to be able to not understand the UI?