New Twiddle

controllers.application.js

import Ember from 'ember';
import { EKMixin, keyUp } from 'ember-keyboard';
export default Ember.Controller.extend(EKMixin, {
  appName: 'Ember Twiddle',
  init() {
  	this._super(...arguments);
    this.set('keyboardActivated', true);
  },
   aFunction: Ember.on(keyUp('alt'), function() {
    console.log('`KeyS` was pressed');
  })
});

templates.application.hbs

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

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1",
    "ember-keyboard": "2.3.0"
  }
}