title: IOS 8 UIDocumentPicker
body: <p>I have some questions regarding the UIDocumentPicker in iOS in terms of how can developer customize the content displaying to the user:
  In the official document, it says there're 2 ways of presenting the Document Picker: </p>
  
  <ol>
  <li>the menu of available storage the most recent used document picker</li>
  <li>the most recent used doc picker.</li>
  </ol>
  
  <p>I'm wondering if there's an option for user to choose what's the 'landing App Container'. For example, if I'm using Pages, I want the Pages folder in the iCloud drive to display first, then the user have the option to return to the main directory and choose other app containers.</p>