Menus on Ubuntu are a little different from regular menu system. There options to enable global menu (so menu will be show on menu bar on top of the screen) and local menu (so menu will be show on window bar). So there's option to always show menus and just when mouse rolls over. The idea is support this menus on Ubuntu so it can have a better behavior.
Enpass is installed inside /opt/Enpass. IMHO should be turn down the upcase, become /opt/enpass. The idea is keep the standrd Unix. Even upcase don't harm, should be a standard.