The good news is that as a more or less standard Android device, you have the vastly superior power and flexibility to use virtually any mechanism available on that platform to do notifications: listen server socket connections, Google push service, 3rd party push service, etc.
The less good news is that Cisco does not provide an IP Phone Services compatible mechanism, or any other special APIs for notification on the device, so you may need to do some development to support the DX devices with a pre-existing IPPS-based application.