so-41947915

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

instance-initializers.root-element.js

import jQuery from 'jquery';

export function initialize(appInstance) {
  appInstance.didCreateRootView = function(view) {
    let containerId = 'ember-container';
    jQuery('<div>').prop('id', containerId).prependTo(jQuery(this.rootElement));
    view.appendTo(`${this.rootElement} #${containerId}`);
  };
}

export default {
  name: 'root-element',
  initialize
};

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
<br>
<br>

twiddle.json

{
  "version": "0.11.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.10.2",
    "ember-data": "2.11.0",
    "ember-template-compiler": "2.10.2",
    "ember-testing": "2.10.2"
  },
  "addons": {}
}