When you uninstall or remove programs from your Mac, they often leave bit behind. iTrash is an uninstall utility that uses a special search algorithm known as the 'Levenshtein Distance algorithm' to find all related files and delete them.
This is because many (although not all) applications install several files and folders throughout your system meaning that deleting an application itself is not enough to make sure you get rid of everything. iTrash features a simple drag and drop interface that allows you to drag applications into it to ensure full removal. If you make a mistake, there's a handy 'Put Back' feature in iTrash for OS X 10.6+, which restores removed files.
Alternatively, you can set iTrash to run in the background in Ghost Mode so that when you drag something into the Trash, iTrash automatically detects the associated files that need to be removed. An additional Expert makes it possible to find related files although this can be a little over zealous in trying to remove files that either aren't associated or shouldn't be removed. iTrash is also suitable for removing Widgets and PrefPanes and can be configured to protect important related applications files (.plist, application support).
iTrash is a powerful tool that removes all of the annoying files and folders that would normally get left behind when you uninstall programs.