at first I have to say that Avast! are creating very good products!
I have suggestion regarding Anti-Theft mobile application for Android. I think that you should implement different password for remote control of mobile device.
Reason for that are many SMS application that show SMS messages in notification bar. If password is visible someone can easily disable Avast!.
I still think that even if this problem with goSMS will be resolved, that sending avast secure code through telephone carrier is not safe. Specially not in plain text. By my opinion there should be “panic code” which would be different than secure code for program (phone) access.