Open Hardware Monitor - Monitors temperature sensors, fan speeds, voltages, load and clock speeds, with optional graph.
BreezoMeter - Health-focused Environmental Intelligence
Guru3D - Guru of 3D: PC Hardware Reviews and tests
World Air Quality Index - Air quality index for the globe
Geforce Experience - GeForce Experience is a new application from NVIDIA that optimizes your PC in two key ways.
Flow by Plume Labs - The smart air quality tracker to help you find clean air