GtkOrphan is described as '(a Perl/Gtk2 application for debian systems) is a graphical tool which analyzes the status of your installations, looking for orphaned libraries. It implements a GUI front-end for deborphan, adding the package-removal capability' and is an app in the OS & Utilities category. There are three alternatives to GtkOrphan for Linux. The best alternative is localepurge, which is both free and Open Source. Other great apps like GtkOrphan are deborphan (Free, Open Source) and debfoster (Free, Open Source).
deborphan finds packages installed on your Debian/GNU system that have no other packages depending on them. Its primary goal (and default action) is to trace unused libraries. A dialog frontend, orphaner, is included in the package for easy removal of packages.
Debian uses the main programs apt and dpkg to manage packages. These programs do not make a distinction between packages that got installed because some other program happened to need it and packages you really asked for.