I've implemented an AllPlay media player service using Windows UWP and it even runs great on a $35 Raspberry using Windows IoT Core. It implements the interfaces net.alljoyn.MCU, net.allplay.ZoneManager, net.allplay.MediaPlayer and org.alljoyn.Control.Volume, and matches the behavior of my Gramofon player.
I even built an app for the Gramofon that controls this service just fine as well, all via AllJoyn.
However... none of the official AllPlay apps discovers my AllPlay service. I'm wondering what other trickery is going on that is used by these apps? Can anyone shed some light on this?
I did notice that my Gramofon exposes two separate devices - no idea why that is - but the second device seems to be more related to system maintenance like firmware update, wifi config etc.
Btw for those who are interested, I've shared the code here:
AllPlay media player service:
Client application for controller AllJoyn devices including AllPlay players: