Mac's don't need defragging as OS X automatically writes 2Gb or below sized files to one contiguous space on the drive. There are certain cases where's it's needed to free up a large spaces on the drive, but not something everyone has to do.
Memory Clean is an app for cleaning up your Mac OS X device memory at intervals. Memory Clean is available from the App Store or several download sites, and installs easily. Memory Clean is a free.
- Want to get right to the point? My top picks for best Mac Cleaning tools and optimization utilities are Smart Mac Care and CleanMyMac X. What Is A Mac Cleaner App? Whether you want to clean up your Mac, boost performance, optimize memory, manage data, clean malware infections, remove junk files, or uninstall apps completely, Mac cleaning apps are the perfect solution.
- Stop your Mac getting bogged down with useless files and memory hogging applications. Clean your Mac with one of these best Mac cleaner apps. We show you the best cleanup utility apps for macOS. Detox My Mac is basically the Mac software cleaner. It is designed to clean up junk stored in the storage space on the Mac and makes the memory space free.
Far as other Mac maintainence, there really isn't any except to backup one's files regularly. Keeping Software Updated and run a web browser check to make sure the plug-ins are current.
Ram Memory Cleaner Mac

Ram Cleaner App Mac
For Safari and Flash, this check is more accurate
Ram Cleaner Mac
Most of those cleaning programs are junk, especially MacKeeper.
If your friend got onto your computer and visited a bunch of adult sites, then I would recommend something like OnyX, doing ALL the cleaning and maintenance aspects and rebooting, perhaps followed by a Disk Utility Erase free space.
Mac Memory Cleaner App
CCleaner beta is out for OS X, used on PC's and combines cleaning and scrubbing of the drive if setup correctly.
Free Ram Cleaner Mac
If your interested in performance, read my post here
Oct 1, 2011 12:37 AM
