AQI - Get air quality updates in your menu bar.
Open Hardware Monitor - Monitors temperature sensors, fan speeds, voltages, load and clock speeds, with optional graph.
CheckMyMac - Hardware and System usage monitor for MAC OS X Intel 64 10.8 +
Guru3D - Guru of 3D: PC Hardware Reviews and tests
Air Matters - Providing real-time Air Quality Index & Allergy Pollen & Weather Data, as well as Protection Recommendations and Forecast.
Geforce Experience - GeForce Experience is a new application from NVIDIA that optimizes your PC in two key ways.