Yes, when using hvv Any, the hvv switch app must be running the entire time and must not be closed, otherwise no data can be recorded for the calculation of the journey. This does not mean that the screen has to be switched on all the time or that no other apps can be used on your smartphone while you are using hvv Any. The hvv switch app must not be closed. If the app is not active for too long (max. 2 minutes) your driving authorisation will be withdrawn.