CleanMyMac X - Clean, protect and speed up your Mac
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.
Outbyte - Outbyte is a cmprehenmsive computer repair tool that is built to address a range of various system issues like clean up your drive, optimize performance and enhance privacy or security.
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?
Tweaking - Tweaking is an all-in-one repair tool, helping you to fix large Windows problems such as registry errors, file permissions, as well as other issues with Internet Explorer, Windows Update, Windows Firewall, and many more.