title: How to know if my app has an instance id/is registered with GCM?
body: <p>I need to know if i have an instance id when my user logs in to the app in a deterministic manner. Is there any other way to know other than <em>trying</em> to get an instance id and handling the possible exception? - That approach is prone to failing because the documentation only mentions an IOException, which might be raised because of a network exception or some other IO error.</p>
  
  <p>I am tracking the value myself with SharedPreferences but that seems a bit fickle as the app may not be used for a bit of time and the value might get out of sync.</p>