title: How to sync android database with web database?
body: <p>Hi I want to sync android database with web database, my scenario is:</p>
  
  <p>I want to make an android app dictionary. The dictionary words are added by web forms and the user android consume those words. In the Android application I have the historical of words that the user displayed and data of their studies, that should be synchronized online in case of change user phone or him have multiple devices.</p>
  
  <p>My question is how to do that: </p>
  
  <p><strong>I need authentication or can get the User's google account to identify him?</strong> </p>
  
  <p><strong>How should I synchronize these two databases?</strong></p>
  
  <p><strong>If I use Backup API i can get the same data in diferents devices?</strong></p>