NightOwl - Easily toggle your Macs Dark Mode with this menubar app.

f.lux - f. lux is a piece of software for Windows, Mac, Linux, iOS, and Android that provides a blue light filter over your screen. Research suggests limiting our exposure to blue light in the hours before bedtime can help us fall asleep faster.

Darkness: Beautiful Dark Themes - Chrome extension that provides beautiful dark themes for Facebook, Google and more.

CareUEyes - CareUEyes is an eye protection software for windows that comes with blue light filter, screen dimmer, and break reminder

Darker Medium - Read Medium stories with happy eyes

Dimmer - A very small and free utility for Windows to reduce brightness on LCD/TFT screens.