AppCleaner is a simple application which ensures your applications, along with any leftover files are deleted properly.

When you install an application in OSX, there are often multiple files installed in the background that might go unnoticed to the typical user. The problem with this is that these files often remain on the computer even after the application is deleted.

To uninstall an application with AppCleaner, all you need to do is drag it into AppCleaner. AppCleaner lists all of the files associated with the application and shows how large each file is. Once you’re happy with the files, all you need to do it click on the delete button.

Source: http://www.freemacsoft.net/appcleaner/