Yeah, sorry for the misleading question. As MacInWin said, the dev has another app called "Maintenance", which is why I'm confused what the difference is between that app and Onxy
A description of Onxy (from the dev's site)
OnyX is a multifunction utility for OS X which you can use to verify the startup disk and the structure of its system files, to run miscellaneous tasks of cleaning and system maintenance, to configure some hidden parameters of many of Apple’s applications, and more.
A description of Maintenance (from the dev's site)
Maintenance is a system maintenance and cleaning utility for OS X which you can use to run miscellaneous tasks of system maintenance: repair permissions, run periodic scripts, rebuild the databases, delete Application, Font and System cache, and more.
As you can see, the sound very similar...