CCleaner - CCleaner cleans, speeds up and frees up space on business endpoints.
CleanMyMac X - Clean, protect and speed up your Mac
Avast Cleanup - Next generation tuneup and cleanup for your PC
DaisyDisk - DaisyDisk is a disk analyzer tool for OS X that visualizes hard disk usage and allows to free up hard disk space.
Advanced System Optemizer - Clean, optimize and personalize your PC
Fossils - Find and clean out all your old unused files