The app access was standard and has beenwas deactivated in 2018 at the end of Q1.
The communication between vehicle and app worked both via mobile (GSM) and via PowerLine. A SIM card was not needed. The communication module is in the footwell of the passenger and is useless since the deactivation, if you want to, you can remove it without having any trouble.
The "app" was a web-based application in which you saw things like the state of charge, the charging process and the "eco-score". In addition you where able to set the time for the pre-conditioning to start.