Open Hardware Monitor - Monitors temperature sensors, fan speeds, voltages, load and clock speeds, with optional graph.
Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.
Guru3D - Guru of 3D: PC Hardware Reviews and tests
ShareX - ShareX is a free and open source program that lets you capture or record any area of your screen...
Geforce Experience - GeForce Experience is a new application from NVIDIA that optimizes your PC in two key ways.
LightShot - The fastest way to take a customizable screenshot.