I know what you mean, I have so many devices in the house that have their own streaming methods - a Sonos speaker in the kitchen, an A/V amp that can play content using wi-fi, Bluetooth or Chomecast, a Kodi box that can stream via bluetooth, a TV that uses (among others) wi-di, Bluetooth headphones and in-car... etc, etc, etc. It'd be lovely if PA could steam seamlessly to any of them, rather than needing to use their own apps.
Andre