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.
MSI Afterburner - Tool to manage video cards. Shows video card stats (temp, GPU usage, etc.).
CareUEyes - CareUEyes is an eye protection software for windows that comes with blue light filter, screen dimmer, and break reminder
ASUS GPU Tweak - ASUS GPU Tweak fully implements TechPowerUp’s GPU-Z analysis and monitoring features.
Dimmer - A very small and free utility for Windows to reduce brightness on LCD/TFT screens.
Guru3D - Guru of 3D: PC Hardware Reviews and tests