Onyx by Titanium - This website provides operating system utilities for macOS
CleanMyMac X - Clean, protect and speed up your Mac
MacPilot - Unlock over 1200 features in Mac OS X and optimize your system!
Fossils - Find and clean out all your old unused files
Alfred - Alfred is an award-winning app for macOS which boosts your efficiency with hotkeys, keywords, text expansion and more. Search your Mac and the web, and be more productive with custom actions to control your Mac.
DaisyDisk - DaisyDisk is a disk analyzer tool for OS X that visualizes hard disk usage and allows to free up hard disk space.