Play music across multiple devices at once
The Airfoil apps from Rogue Amoeba will almost certainly do everything you want, including sending the audio to iOS devices, AppleTVs, Macs and even Bluetooth speakers and Google Chromecast devices, all at the same time and in sync. Airfoil Satellite lets Macs, Windows, and iOS devices act as speakers for the Airfoil and Airplay sources.