CCleaner - CCleaner cleans, speeds up and frees up space on business endpoints.
Klima - Go carbon neutral
BleachBit - When your computer is getting full, BleachBit quickly frees disk space.
Website Carbon Calculator - Find out the how much CO2 your website emits
AVG PC TuneUp - Peak performance for your PC. Keeps it going for longer. - More Speed Turbo Mode
Padbury Clock Screensaver - Minimal screensaver for Mac