You're launching an Activity to make the notification, it makes sense that at first you see an empty Activity - that's exactly what you just launched. Use a BroadcastReceiver instead.
So when it receives:
public class Receiver extends BroadcastReceiver{
@Override
public void onReceive(Context context, Intent intent)
{
NotificationManager mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context);
mBuilder.setContentTitle("Your fuel may be running low.")
.setContentText("There are 30 mins left on your timer. Check your fuel gauges.")
.setSmallIcon(R.drawable.ic_launcher);
Intent intent = new Intent(context, FuelTimer.class);
PendingIntent in = PendingIntent.getActivity(context, 0, intent, 0);
mBuilder.setContentIntent(in);
mNotificationManager.notify(0, mBuilder.build());
}
}
You will have to add the Receiver to the manifest:
<receiver android:name="com.YouForgotWhat.FlightGear.Receiver" >
<intent-filter>
<action android:name="com.YouForgotWhat.FlightGear.DisplayNotification" />
</intent-filter>
</receiver>
Lastly, change you code to launch the receiver, so it is like
//PendingIntent to launch activity when the alarm triggers.
Intent intent = new Intent("com.YouForgotWhat.FlightGear.DisplayNotification");
PendingIntent displayIntent = PendingIntent.getBroadcast(getBaseContext(), 0, intent, 0);