Edit in JSFiddle

var app = angular.module('myApp', []);

app.factory('Loader', function ($rootScope, $timeout) {
  return {
    init: function (num) {
      var rnd = Math.ceil(Math.random() * 1000 * i);
      // Launch each num timer
      for (var i = num; i > 0; i--) {
        $timeout(

        function () {
          $rootScope.$broadcast('RessourceLoaded')
        }, rnd);
        rnd = Math.ceil(Math.random() * 10000);
      }
    }
  };
});

function MainCtrl($scope, Loader) {
  $scope.status = "Chargement en cours";

  $scope.$on('RessourceFinish', function (event) {
    $scope.status = "Chargement terminé!!! :D";
  });
}

function LoaderCtrl($rootScope, $scope, Loader) {
  $scope.numRessource = 50;
  $scope.numRessourceLoaded = 0;

  $scope.$on('RessourceLoaded', function (event) {
    $scope.numRessourceLoaded++;
    if ($scope.numRessourceLoaded == $scope.numRessource) {
      $rootScope.$broadcast('RessourceFinish');
    }
  });

  Loader.init($scope.numRessource);
}

<h2>Loader</h2>

<div ng-controller="MainCtrl">{{status}}</div>
<div ng-controller="LoaderCtrl"> <pre class="prettyprint"><center>{{numRessourceLoaded}}/{{numRessource}} ({{numRessourceLoaded*100/numRessource}}%)</center></pre>

</div>