Funny thing just happened: I turned off AirPlay Receiver, started my service on port 5000, turned AirPlay Receiver back on, it is now happily listening on port 54842 in addition to port 7000 on which it was also listening before.

I have published the source code of the project, it's at this URL which I apparently can't include as a link… git.morpheu5.net/Morpheu5/yDnab-iOS EDIT UGH, this is NOT the answer, I clicked on the badge by mistake, how do I unmark it?!