Serviio

Why is not possible to create users and passwords for each new user? I paid for full version of this app but cannt create users.... very strange.

Mainly because that functionality is not included. Yes, some others have such permissions, and there has been requests for such here, although I believe only to control access to MediaBrowser. Having a login for your Smart TV (for example) is likely not possible, as that would require authentication to be built into the TV client, and there's nothing Serviio can do to alter that.

The main thing you get with the paid version is access to MediaBrowser. I believe there's a few other items, but MB is the big one. That allows you to access your files from outside your network if you desire. I use it on occasion when I travel. There's rarely anything I ever want to watch on any of the hotel TV channels.