title: Is it possible to detect Android app uninstall?
body: <p>My app is using Google's C2DM (push notification) to notify users about new activity from friends. Once they install the app I register the device with C2DM servers and store user's phone number. So I know that the user is using my app and I can send him/her the push notifications. But what happens if users uninstalls my app, is there a way to catch it in my app? Or the only way is to catch an error on my server when I send a C2DM and it's unreachable, then mark a user as inactive? </p>
  
  <p>I would love to notify users when their friends are using an app and when they no longer do.</p>
  
  <p>What's is the best solution for this scenario?</p>