You may have noticed if you opened up /client/app/admin/admin.controller.js that it calls the Auth module like so:
.controller('AdminCtrl', function ($scope, $http, Auth …
You can include Auth in your other controllers the same way. It's pretty useful to have Auth available in your controller to detect if a user is logged in, or to get information about the current user. In the body of your controller you can add
$scope.getCurrentUser = Auth.getCurrentUser;
$scope.isLoggedIn = Auth.isLoggedIn;
And then you can use isLoggedIn() or getCurrentUser() in the HTML view for your controller!