Usic Ionic instance somewhere else

.run(function($ionicPlatform, $http,config) {
$ionicPlatform.ready(function() {

var device_token = localStorage.getItem('device_token');
  var push = new Ionic.Push({
    "debug": true
  push.register(function(obj) {



Above code is working fine. But how do I register the token other controllers? means no within the run() of ionic? In my case I would like not to register the token when the app launch, but when user interact with some part of the app.