Clean your Mac of old clutter. Clear up your recycle bin, temporary files and folders, broken permissions and more. Remove installed programs with the click of a button. Advertisers and websites track your behavior online with cookies that stay on your computer. CCleaner erases your browser search history and cookies so any. “System” as defined by CleanMyMac includes user cache files, system log files, as.
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.
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.
For Safari and Flash, this check is more accurate
With this app in place, you can just download and watch what you want, without having to worry about formats, compatibility, and conversions. Lvc for mac. ProsVersatile and free: VLC Media Player is completely free, and it allows you to play media in a wide variety of formats, many of which would not otherwise be immediately compatible with Mac. In this way, it eliminates the need to convert files before you can play them back and lets you get right down to the fun part.Advanced features: While most users will probably only use this app to watch media, it does offer a few nice advanced features that more experienced users will enjoy.
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.
Cleaners For Mac Os X 10.7
CCleaner beta is out for OS X, used on PC's and combines cleaning and scrubbing of the drive if setup correctly.
Mac Cleanup App
If your interested in performance, read my post here
Cleaner For Mac Os X 10.6.8