When you uninstall an Android app (that removes the app in the android container), the corresponding Ubuntu Touch icon on the app scope will still be there and needs to be removed manually (for now?).
Those are stored in /home/phablet/.local/share/applications/ and IIRC all Android apps starter files begin with anbox (or was it android or apk?; you'll get it once you see it ).
@jmarshallh yes, Nexus 5 is still a little beast I use it as my daily driver.
Keep in mind that not all kind of software runs smoothly in Libertine yet. For example, Firefox doesn't work at all because there's an upstream bug.