AppCleaner does a much more thorough job removing unwanted applicated compared to the default method. This saves space and potentially speeds up your Mac.
AppTrap isn't really an app itself. It doesn't sit in the dock or the menu bar, and it only does one thing. It's a lightweight background process that runs silently until it detects an app deletion. Once an app is deleted, AppTrap automatically rounds up any related files and presents them in a dialog where a user can select which files to keep and which to discard. Unlike many similar tools there is no need to drag an app onto the tool for it to work. Simply trash the application as usual and the AppTrap will respond.
AppTrap is a set-it-and-forget-it style tool. There is an option to have the process start automatically on login, and once running it stays out of sight until an app deletion is detected.
AppDelete plain and simple performs very well in the way it thoroughly cleans out the files that are part of the app that exist in other sections of the filesystem.