How to completely delete a program off a mac.

AppZapper works great for deleting all the prefs and things. It is very simple to use and has a window that pops up showing what files it thinks should be deleted so you can verify it before it proceeds. Check out their site; it will show you a screen shot of what it looks like in action. I think AppDelete works similarly and there are other products out there as well.

Not sure about your second question, sorry. I have always kept an eye on my uninstalls so I haven't had a need for it. Aside from some clutter I don't think orphaned files can cause any problems because OS-X does not have a Windows like registry that it has to parse through during startups, installs, and God knows how often in between. If you can't find anything that can scan your system for old, unused app files, you can take a peak in your Library-Application Support and PreferencePanes folders for related junk files if it makes you sleep better. Unlike Windows, OS-X does not suffer the my-system-is-slowing-as-the-months-pass syndrome. Although, to be fair about it, my Win7 box at work has shown no signs of slowing so perhaps Microsoft has worked out those bugs.

 

In most cases, app removal software like AppZapper, AppCleaner, etc. doesn't do a thorough job of deleting files/folders related to deleted apps. For more information, read this.

The most effective method for complete app removal is manual deletion:

Best way to FULLY DELETE a program​

One app that I would not recommend, based on the number of complaints that have been posted in this forum and elsewhere, is CleanMyMac. As an example: CleanMyMac cleaned too much.

You don't need "cleaner" apps to keep your Mac running efficiently. Mac OS X does a good job of maintaining itself, without the need for 3rd party apps. Many have successfully used Monolingual to remove unwanted languages and architectures to free up drive space, but even that will not make your Mac run faster.

Be aware that extreme caution should be exercised when using such apps, as deleting certain languages or architectures can create significant problems. At best, deleting these things may buy you 1-2GB of drive space, but will not improve your system's performance. If you're not certain about what you're doing, don't delete anything. The small drive space savings are not worth the risk of potential problems.

 

99% of apps just need to be dragged to the trash.

spending hours tracking down a few megs of completely harmless preferences files is a waste of time.

Forget about them.

 

I'm currently using AppCleaner, I also have MacKeeper installed and tried AppZapper, but I found AppCleaner works best for me.

 

Read my earlier post about such apps. They're not effective.

 

See this thread:

http://forums.macrumors.com/showthread.php?t=1227036