CCleaner - CCleaner cleans, speeds up and frees up space on business endpoints.
CleanMyMac X - Clean, protect and speed up your Mac
Glary Utilities - The No. 1 Free, Powerful and All-in-one utility for cleaning your PC
Fossils - Find and clean out all your old unused files
BleachBit - When your computer is getting full, BleachBit quickly frees disk space.
DaisyDisk - DaisyDisk is a disk analyzer tool for OS X that visualizes hard disk usage and allows to free up hard disk space.