This is a bit strange. When I search this issue online I see many pages of Google results and SO solutions... but none seem to work!
In a nutshell, I am trying to
You are trying to reference a controller that is part of a separate module. In order for this to work, you need to inject your secondary module (addEntry) into your main module (nav):
var app = angular.module('nav', ['ui.bootstrap', 'addEntry']);