DaisyDisk - DaisyDisk is a disk analyzer tool for OS X that visualizes hard disk usage and allows to free up hard disk space.
Website Carbon Calculator - Find out the how much CO2 your website emits
CleanMyMac X - Clean, protect and speed up your Mac
Wren - Offset your carbon footprint by saving rainforests
MacFly Pro - Smart assistant for better Mac performance
Klima - Go carbon neutral