ui update

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  isLoading: false,
  counter: 0,
  actions: {
  load: function() {
    var counter = 0;
    
  	this.set('isLoading', true);
    
    Ember.run.next(() => {
    
	    while(counter < 500000) {
  	    counter += 1;
  
		  this.set('counter', counter);
    	}
    
   	 this.set('isLoading', false);
    });
  }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}f</h1>
<br>
<br>
{{isLoading}}
<br>
<br>
{{counter}}
<br>
<br>
<button {{action 'load'}}>
load
</button>

{{outlet}}
<br>
<br>

twiddle.json

{
  "version": "0.8.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.5.1",
    "ember-data": "2.5.2",
    "ember-template-compiler": "2.5.1"
  }
}