This 2016 post describes AirPlay in Multi Room Audio Player 5. The feature has been rebuilt in MZAP 7 — see AirPlay input and streaming zones for how it works now.
Finally, we’ve added Apple Airplay support to Multi Room Audio Player. Now you can wirelessly stream your iTunes music library from iPad, iPod or iPhone directly to any room using our software. Please read about Airplay wireless streaming technology.
[+] Added: Apple Airplay support;
[+] Added: New Scheduler event Load Playlist to Player;
[-] Fixed: Internet radio station playback in M3U playlist.
You can view all version history here.
Apple, iPod, iPad, iPhone, and AirPlay are trademarks of Apple inc., registered in the U.S. and other countries.
P.S. Unfortunately, but iOS9 not supported yet 🙁