Dimmer - A very small and free utility for Windows to reduce brightness on LCD/TFT screens.
ControlMyMonitor - View and modify the settings of your monitor from command line or GUI
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.
Red Moon - Screen filter for night time phone use.
myPoint Shade - Stop burning your eyes! myPoint Shade is caring for your eyes' comfort.