Which app specific prevents moving to external storage? Subject. I'm not asking what I will lose if I move app, but rather about how system detects if app is "movable" or not and enables/disables corresponding button in "App Info" activity accordingly. Hope I made myself clear, if now - please comment and suggest better terminology.
Okay, this is related to App Install Location and behavior in question controlled by application manifest, specifically, by android:installLocation attribute (NB: by default system assumes internalOnly).