SDelete - Securely overwrite your sensitive files and cleanse your free space of previously deleted files using this DoD-compliant secure delete program.
CCleaner - CCleaner cleans, speeds up and frees up space on business endpoints.
AppCleaner - AppCleaner is a small application which allows you to thoroughly uninstall unwanted apps. Installing an application distributes many files throughout your System using space of your Hard Drive unnecessarily.
Clean Master - Some users swear by it, some call it a glorified snake oil that does more harm than good. That can be said about any snake oil, but what specific brand of snake oil can boast almost a billion downloads around the world?
CleanMyMac X - Clean, protect and speed up your Mac
Avast Cleanup - Next generation tuneup and cleanup for your PC