title: Tracking days a user is using an Android trial application
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/995719/android-trial-applications">Android Trial Applications</a>  </p>
  </blockquote>
  
  
  
  <p>I'm trying to create a trial application, which allows the user to use the service for, say, 30 days.
  Is there a way to keep track of this on the device itself without the user being able to alter or delete the data?</p>
  
  <p>Using SharedPreferences for example would enable the user to remove app data in settings -> applications, or a simple uninstall - install would remove this data.</p>