title: how to use UTImportedTypeDeclarations in our app
body: <p>i need some help here, i want to make my app can open all file types from another app, just like Open In feature in IPAD, is it true to use <code>UTImportedTypeDeclarations</code> ?</p>
  
  <p>but i dont know what to do, is there any tutorial to use it?
  thank you</p>