Currently the only way to stream to multiple airplay receivers (especially using a mobile control device) is

a) run Remote app on iOS, connect to iTunes library on a desktop PC (PC plays audio to remote receivers)
b) run Airfoil on PC, send audio from iOS to Airfoil Speakers on PC, Airfoil Speakers routes to Airfol, Airfoil sends to multiple Airplay receivers

it'd be great to be able to remove the PC from the equation. And with option B the audio has to be streamed wirelessly from the phone first to the PC. Option A is better as the audio tends to be coming from a wired desktop machine

I think forked-daapd allows for multiple receivers but I've had trouble getting it to run stably.

Interested to see what mpd/raspyfi can do instead.

thanks
j