title: Determine date (or version) that app was purchased from Google Play Store - equivalent of iOS appStoreReceiptURL
body: <p>I'd like to determine which version of my Android app a user originally purchased from the Google Play Store.  I need this info to help support moving from a paid app model to a freemium model.</p>
  
  <p>In iOS7 onwards, you can do this by using <code>[NSBundle appStoreReceiptURL]</code> which returns a URL of the App Store receipt that can be examined.</p>
  
  <p>Is there an equivalent in the Google APIs?</p>