Hello @brandyshea,
Currently clicking on the hardware back button put the application on background, my client want me to show a toast with the message click again "Press back button again to exit", So i have gone through the url below and found this can be done by these two function with the description "Methods meant to be overridden by the engine", there is no example of using these function.
- onHardwareBackButton() {}
- registerBackButtonAction() {}