Angular: Empty Fiddle

http://angularjs.org/

HTML

<script src="http://code.angularjs.org/angular-1.0.1.js"></script>
<div id="app1">
    App {{0+1}}
    <div ng-controller="MainCtrl">
      {{hello}}
      {{test}}
    </div>
</div>    

<div id="app2">
    App {{1+1}}
    <div ng-controller="MainCtrl">
      {{hello}}
        <input type="text" ng-model="test"/>
    </div>
</div>

CSS

div {
            border: dashed 1px #000;
        margin-bottom: 10px;
        padding: 10px;
}

JavaScript

angular.element(document).ready(function () {
        angular.bootstrap(document.getElementById('app1'), ['app1']);
        angular.bootstrap(document.getElementById('app2'), ['app2']);
      });

angular.module('app1', []);
angular.module('app2', [])

angular.module('app1')
  .controller('MainCtrl', function ($scope) {
    $scope.hello = 'I am Controller 1';
  });


angular.module('app2')
  .controller('MainCtrl', function ($scope) {
    $scope.hello = 'I am Controller 2';
    $scope.$watch('test', function (newVal) {
      var el = document.getElementById('app1');
      var scopeApp1 = angular.element(el).scope();
        if (!scopeApp1.$$phase) {  
        scopeApp1.$apply(function () {
          scopeApp1.test = newVal;
        });
        }
    });
  });