Mac OS X diagnostics software like CCleaner?

Onyx and MainMenu are 2 handy programs that allow you to clean up OS X a bit. OS X doesn't tend to clog up like Windows. There's no registry. Every application keeps its preferences in its own folder in "plist" files. Still, things can get mildly out of whack from time to time. I've used both Onyx and Mainmenu on my Mac.

I've also read good things about Yasu, but I haven't gotten around to giving it a try.

I should also mention that there is plenty of freeware available for OS X cleanup and maintenance. Steer clear of expensive bloated solutions, particularly those offered by Norton and other companies that normally write for Windows.

 

Cocktail has a very good reputation although its not free. I've not looked into it enough to know what it has over Onyx; they seem to offer pretty much the same thing. Paying for Cocktail may give you a little more reassurance for something which can potentially wreak havoc with your Mac.

 

Associated Deleted File Cleaning up

Cleaning up associated files for deleted apps I use apptrap runs in the background you hardly know its there until you delete something.