I have an SMS blocker Android application developed myself which was working quite well capturing all the spams until recently Google updated its Hangouts app to work with S
When you register receiver, set priority of filter to INTEGER.MAX_VALUE. Now abortBroadcast() will work;
receiver = new HightPrioritySmsReceiver();
IntentFilter filter = new IntentFilter("android.provider.Telephony.SMS_RECEIVED");
filter.setPriority(Integer.MAX_VALUE);
registerReceiver(receiver, filter);