Wikipedia
CleanMyMac is a utility application developed by Macpaw for the Mac OS X operating system, first released in 2009 and updated in 2015, which can automate or simplify removal of unnecessary files.
The software can identify and delete unnecessary files on the Mac OS X startup disk, including system files, log files, cache files, language files, universal binaries, old iOS software updates, and temporary iPhoto files. This can be done on a scheduled basis. An uninstaller allows old or incompatible applications to be thoroughly deleted, and an extension manager allows unwanted browser extensions to be disabled or deleted. The software offers the ability to bypass the trash when deleting files, and securely erase sensitive material.
The original version of the application was downloaded over three million times. An updated version, CleanMyMac2, was released on March 5, 2013, featuring a redesigned user-interface, an iPhoto library cleanup tool, a large and old file finder (for potential deletion), OS X Mavericks compatibility and performance improvements. The newest iteration, CleanMyMac 3, version 3.0.2, was released by MacPaw on May 8, 2015. The application requires OS X 10.8 Mountain Lion or higher and about 45MB of free hard drive space. According to MacPaw support, they have released a beta version of CleanMyMac 3 with macOS 10.12 compatibility. The beta version will only be available once Apple officially launches macOS Sierra to the public. The software supports ten languages.