Listening for All Sub Properties

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  obj: Ember.Object.create({thing: 'Foo'}),
  objThing: Ember.computed('obj.[]', function() {
    return this.get('obj.thing');
  }),
  init: function() {
    this._super();
    Ember.run.later(() => {
      console.log('ran');
    	this.set('obj.thing', 'Bar');
    }, 100); 
  }
});

templates.application.hbs

<h1>{{objThing}}</h1>

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"
  }
}