title: How to create directory on FirefoxOS apps in FirefoxOS device?
body: <p>I my application to create a directory on a FirefoxOS device.</p>
  
  <p>Anyone knows how to do that?</p>
  
  <p>[Addition] how to create file</p>
  
  <ol>
  <li>[SDCard] = navigator.getDeviceStorage( 'sdcard' )</li>
  <li>[Blob Object] = new Blob()</li>
  <li>[SDCard].addNamed( [Blob Object], fileName )</li>
  </ol>