Dimmer - A very small and free utility for Windows to reduce brightness on LCD/TFT screens.
CareUEyes - CareUEyes is an eye protection software for windows that comes with blue light filter, screen dimmer, and break reminder
PangoBright - Screen dimming software that allows you to control the brightness of your laptop screens as well as external monitors.
CF.lumen - CF.lumen is a powerful app for Android that adjusts the colors by detecting the position of the sun or according to custom settings.
Eye Saver - Free software for eye protection and more!
Lux Auto Brightness - Lux Automatically Adjusts Your Screen Brightness