I have a rooted Android which runs an application called AllCast, it allows me to stream music from YouTube via Airplay to a number of devices in the home.
I’m wondering if theres some way of exposing the application inside Habpanel or OH2 some how to try and obtain a single pane of glass for my automation?
Well, HABPanel is just a web page as far as your display is concerned. There is no way for it to interact with any of the apps on your phone. But if you set up Tasker you can do something along these lines:
HABPanel -> openHAB -> AutoRemote -> Tasker -> Allcast
But this assumes that Allcast has intents or the ability to do anything more than just launching the app.