Some GUI programs don't show up in menu

I have noticed that some apps with gui interface don’t show up in the desktop menu. Ex. the ‘wnb’ app from wordnet. I am wondering if we can make an automatic script that find all gui apps and check if they are in the menu? Maybe by finding package that link to a known gui interface libraries, then all we need is a list of all gui libraries. Anyone that have looked into this before???