TinkerTool - Tinker with the hidden settings of your Mac
CCleaner - CCleaner cleans, speeds up and frees up space on business endpoints.
Onyx by Titanium - This website provides operating system utilities for macOS
Glary Utilities - The No. 1 Free, Powerful and All-in-one utility for cleaning your PC
Cocktail - General purpose system modify/repair utility
BleachBit - When your computer is getting full, BleachBit quickly frees disk space.