title: Unbind service in android.app.Application
body: <p>In the application in <code>onCreate()</code> I bind to <code>InAppBillingService</code>. There is no <code>onDestroy()</code> method in the <code>Application</code> class. </p>
  
  <p>How to implement the call to <code>unbindService()</code> after the application is closed? </p>