@Jaddy I somehow thought they kicked out the private channels at some point. Sadly, the last time I checked, the site didn't work well on my TV (and they don't bother to offer an app either).
Nonetheless, good to know, thanks for tip! :)
@esureL I just checked: There are apps for iOS, Android and Windows.
I currently use zattoo.com with Chrome and stream to a Chromecast.
FireTV works standalone (I got one for my mother).
Generalistic and moderated instance.