I have recently started trying to set up a working appimage on my 4Gb flash drive without any success. I have downloaded the latest AppImageAssistant, made a folder called AppDir on my flash drive, in that folder copied the zenmap .desktop contents from this site to zenmap.desktop in my AppDir, made ./usr/bin ./usr/share and ./usr/lib, put the zenmap executable from this site (renamed "zenmap") in ./usr/bin/, and put the zenmap icon (renamed "zenmap.png") in ./usr/share/icons/default/48x48/. AppImageAssistant still doesn't recognize AppDir as an AppDir. Why not? What do I have to do?