Authentication System - AngularJS & Ionic Framework - Concerns & DRY & Optimization

I am building a small mobile app using ionic framework and angularJS. It will consume a Restful Web Service that requires authentication (User token). This means I need to keep my users token by myself. Could anyone tell me if there is room for improvement in my code. Specifically regarding to my "Session" service which I feel kind of useless. I based my development in this article.

.run(function ($rootScope, EVENTS, AuthService) {
  $rootScope.$on('$stateChangeStart', function (event, next) {
    if (next.requiresAuth === true && !AuthService.isAuthenticated()) {
      event.preventDefault();
      $rootScope.$broadcast(EVENTS.notAuthenticated);
      console.log('You can not access here without login in.');
    }

  });
})
.constant('apiAddress', 'http://api.test.com')
.constant('EVENTS', {
  loginSuccess: 'auth-login-success',
  loginFailed: 'auth-login-failed',
  logoutSuccess: 'auth-logout-success',
  sessionTimeout: 'auth-session-timeout',
  notAuthenticated: 'auth-not-authenticated',
  signupSuccess: 'auth-signup-success'
})
.service('Session', function() {
  this.create = function(user) {
    this.user = user;
  };
  this.destroy = function() {
    this.user = null;
  }
  return this;
})
.factory('AuthService', function($http, $rootScope, $localstorage, Session, apiAddress, EVENTS) {
  var authService = {};
  authService.login = function(credentials){
    return $http.post(apiAddress + '/users/', credentials).then(function(res) {
      Session.create(res.data);
      $localstorage.setObject('user', res.data);
      return res.data;
    });
  };
  authService.signup = function(signForm){
    return $http.post(apiAddress + '/users/', signForm).then(function(res) {
      $rootScope.$broadcast(EVENTS.signupSuccess);
      return res.data;
    });
  };
  authService.logout = function(){
    Session.destroy();
    $localstorage.destroy('user');
    $rootScope.$broadcast(EVENTS.logoutSuccess);
  };
  authService.isAuthenticated = function() {
    return !!Session.user;
  };

  return authService;
})
controller('appCtrl', function($scope, $rootScope, $state, AuthService, EVENTS, $localstorage, Session) {
  $scope.currentUser = null;
  $scope.isAuthorized = AuthService.isAuthorized;
  $scope.setCurrentUser = function (user) {
    $scope.currentUser = user;
  };
  function logout() {
    AuthService.logout();
  }
  function redirectToLogin() {
    $state.go('login');
  }

  if ($localstorage.isSet('user') && Session.user == null) {
    Session.create($localstorage.getObject('user'));
    $scope.setCurrentUser($localstorage.getObject('user'))
    $state.go('cobranzas.clientes.index');
  }
  // We listen to auth related broadcasts.
  $scope.$on(EVENTS.notAuthenticated, logout);
  $scope.$on(EVENTS.sessionTimeout, logout);
  $scope.$on(EVENTS.signupSuccess, logout);
  $scope.$on(EVENTS.logoutSuccess, redirectToLogin);
})
.controller('loginCtrl', function($scope, $rootScope, $state, EVENTS, AuthService) {
  $scope.credentials = {
    username: '',
    password: ''
  };
  $scope.login = function (credentials) {
    AuthService.login(credentials).then(function (user) {
      $rootScope.$broadcast(EVENTS.loginSuccess);
      $scope.setCurrentUser(user);
      $state.go('index');
    }, function () {
      $rootScope.$broadcast(EVENTS.loginFailed);
    });
  };
})
.controller('signupCtrl', function($scope, $rootScope, $state, EVENTS, AuthService) {
  $scope.signForm = {
    FirstName: '',
    LastName: '',
    Password: '',
    Country: '',
    Phone: '',
    Gender: '',
    Position: ''
  };
  $scope.signup = function (signForm) {
    AuthService.signup(signForm).then(function (data) {
      $state.go('login');
    }, function (data) {
      console.log("Failed");
    });
  };
})

I dont feel right storing user in scope and in the service. Also I feel weird verifying localstorage in app controller. (App controller is a controller placed high at DOM so it's inherited by the others). Thanks you all very much!!!!