The are manual methods to clear off unnecessary data off of your Mac that are safer and you have complete control over your Mac and not just leave a piece of auto cleaning software in charge of clearing off data off of your Mac. Plus, these type of apps aren't really necessary. or anything like these apps, installed on your Mac, while they appear to be helpful, can do too good a job of data 'cleanup' causing the potential to do serious data corruption or data deletion and render a perfectly running OS completely dead and useless leaving you with a frozen, non-functional Mac. Clean, TuneUpMyMac, Mac Optimise, MacCleanse, Memory Clean, App Cleaner/Zapper, etc. Apps like MacKeeper or any other maintenance apps like CleanMyMac 1 or 2, Dr.