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.
MacKeeper - The new MacKeeper app delivers multilayered protection from malware, online threats, and identity theft & Mac performance optimization. Learn what is MacKeeper.
CCleaner - CCleaner cleans, speeds up and frees up space on business endpoints.
MacCleaner Pro - MacCleaner Pro is a bundle of 6 apps to clean up disk space and speed up Mac.
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?