New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  actions: {
  	downloadJSON() {
      let payload = JSON.stringify({ foo: 'bar' });
      let blob = new Blob([payload], { 
        type: 'text/json' 
      });
      
      let blobUrl = URL.createObjectURL(blob);
      let link = document.createElement('a');
      
      link.href = blobUrl;
      link.download = 'download.json';
      
      document.body.appendChild(link);
      
      link.dispatchEvent(new MouseEvent('click'));
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
<a {{action 'downloadJSON'}}>Download JSON</a>
<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"
  }
}