How to use timer with socket.io factory in angular js?

I am trying to use timer with socket.io in angular js but its not working. I am able to send data from node server to client, also i am getting the alert properly but my timer is not working.

Angular Code

var app = angular.module('MyTimerApp', ['ngRoute', 'timer']);

app.config(['$routeProvider', function($routeProvider) {
  $routeProvider.when('/', {
    templateUrl: '/index.html'
  });
}]);

app.factory('socket', ['$rootScope', function($rootScope) {
  var socket = io.connect();
  return {
    on: function(eventName, callback){
      socket.on(eventName, callback);
    },
    emit: function(eventName, data) {
      socket.emit(eventName, data);
    }
  };
}]);


app.controller('MyController', function($scope, socket) {

    socket.on('StartTimer', function(data) {
        alert('Starting Timer');
        $scope.$broadcast('timer-start');
    }); 
});

I have added below lines in my html code.

<div class="timer">
    <h4><timer> minutes,  seconds.</timer></h4>
</div>

Also following dependencies added.

<script src="../node_modules/angular-timer/dist/assets/js/angular-timer-bower.js"></script>
<script src="../node_modules/angular-timer/dist/assets/js/angular-timer-all.min.js"></script>