This past March, Apple introduced a function called Night Shift for the iPhone and iPad, which mimics f.lux in shifting the screen's emitted light “to the warm end of the spectrum” around sunset. So far no researchers have tested f.lux or Apple's Night Shift in a controlled study, but Figueiro says she is planning to conduct such experiments, and Michael Herf says he is collaborating with university scientists to examine the effects of f.lux in everyday environments outside the laboratory.
Recall I tried the f.lux stuff last year, and the reduced light fired off my Seasonal Affective Disorder (which some believe is myth) to a scary degree. SO depressed. Once I stopped using it, it took a week to two weeks to rebalance myself. Lots of vitamin D, both ingested and natural.