CCleaner - CCleaner cleans, speeds up and frees up space on business endpoints.
CleanMem - CleanMem keeps memory use in check on the system without the memory being pushed to the page file.
CleanMyMac X - Clean, protect and speed up your Mac
Fossils - Find and clean out all your old unused files
WinZip System Utilities Suite - Top-rated PC utility software to clean, update, maintain and protect your PC for good. Free Download for Windows and Mac.
DaisyDisk - DaisyDisk is a disk analyzer tool for OS X that visualizes hard disk usage and allows to free up hard disk space.