Example

application.controller.js

import Ember from 'ember';

export default Ember.Controller.extend({
  init() {
    this._super();
    // alert(this.get('p'));
  },
  appName: 'Ember Twiddle',
  queryParams: ['p']
});

application.template.hbs

<h1>Welcome to {{appName}}</h1>
<br>
{{input type="text" value=p}}
p: {{p}}

twiddle.json

{
  "version": "0.6.5",
  "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/2.4.3/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.4.0/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.4.3/ember-template-compiler.js"
  }
}