New Twiddle

application.controller.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Jumping Balls',
  jumpingBalls: [{"newBall": true}],
  ball: {"newBall": true},
  actions: {
		
	}
});

application.template.hbs

<h1>Welcome to {{appName}}</h1>
<br>
{{jumping-balls jumpingBalls = jumpingBalls }}

{{outlet}}
<br>
<br>

components.jumping-balls.js

import Ember from 'ember';

export default Ember.Component.extend({
  didInsertElement: function () {
		var that = this;
   // setInterval(function(){ 
    //	that.send("addBalls");
    //}, 5000);
  },
  init: function () {
  	var tmp = '<div style="cursor:pointer" {{action "addBalls"}}>Add new balls</div><br/><div class="canvas">{{#each jumpingBalls as |ball|}}<div class="ball"></div><br/>{{/each}}</div>';
    this.set('layout', Ember.Handlebars.compile(tmp));
    this._super();
  },
  actions: {
  	addBalls: function () {
        for (var i = 0; i < 5; i++) {
          	this.get("jumpingBalls").pushObject("");
        }
      }
  }
});

styles.app.css

body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}
.canvas {
	border: 1px solid black;
  width:100%;
  height:300px;
  overflow:auto;
}
.ball {
  border:thin solid black;
  width:25px;
  height:25px;
  border-radius:66%;
  background:orange;
}

twiddle.json

{
  "version": "0.5.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.2.0/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.2.0/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.2.0/ember-template-compiler.js"
  }
}