title: Programmatically expanding iOS dictionary app lexicons
body: <p>There is an app in the Apple App Store that downloads custom dictionaries and programmatically adds them to the iOS's built-in Dictionary.app without user intervention. It works normally with the stock ROM, i.e. no jailbreak or anything of that sort is required.</p>
  
  <p>I wonder how this is possible since Apple has never documented such a "feature." There is no API or  hints in the iOS and Dictionary.app documents to explain how this is done.</p>
  
  <p>How could this be implemented?</p>