New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: '4routeAmri',
  test: 10,
  numArr: [1,2],
  compProp: Ember.computed(function() {
  	return 100;
  }),
  actions: {
    add() {
      console.log(this.get('compProp'));
      this.compProp=200;
      console.log(this.get('compProp'));
      this.get('numArr').push(1);
      this.set('test', this.get('test')+1);
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<button {{action "add"}}>add</button>
<br>
{{#each numArr as |num|}}
<li>{{num}}</li>
{{/each}}
<br>
test:{{test}}
<br>
{{compProp}}
{{outlet}}
<br>
<br>

twiddle.json

{
  "version": "0.10.2",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.7.0",
    "ember-data": "2.7.0",
    "ember-template-compiler": "2.7.0"
  },
  "addons": {}
}