a tool can be registered to appear in a flap
for an example:
Flaps registerQuad: #(FileList2 openMorphicViewInWorld 'Enhanced File List' 'A nicer File List.') forFlapNamed: 'Tools'. Flaps replaceToolsFlap
two lines: Flaps unregisterQuadsWithReceiver: FileList2 fromFlapNamed:'Tools'. Flaps replaceToolsFlap
Note: after registering or unregistering, the flap need to be manually recreated see Flaps classreplace*Flap methods