title: Smart App Updates on Google Play Store: how does it work?
body: <p>The Google Play store supports (since Aug 2012) a new feature called Smart App Updates, that allows downloading only the necessary "delta" when upgrading an app.</p>
  
  <p>I have found no documentation for developers regarding this feature, thus I don't know how to optimize my app to make sure it benefits from this great mechanism.</p>
  
  <p>So, does anyone know:</p>
  
  <ul>
  <li>What are the technical impacts (if any) that would be good to know for the developers? 
  (I suppose a new, full-size APK is built on the user's device, or maybe the unchanged data is stored somewhere else?)</li>
  <li>Is the reutilization of unchanged data from the previous versions limited to certain resources? (like files in the <code>asset</code> folder)</li>
  </ul>