So there’s a button if you’re on desktop to get Telescopius to open your Stellarium instance. If I’m on my phone and on the move, all I have is the Stellarium Android app.
No idea if it’s possible and if that app has an API or something else you could hook into, but it’d be great if when you’re on the Telescopius Android app, it’d open Stellarium Android as well.
To connect to Stellarium, its Remote Control plugin needs to be enabled, but I believe the mobile version of Stellarium doesn’t have plugins - at least that was true some time ago when I checked.
You can still use Telescopius on your phone to connect to Stellarium instances running on other devices (provided their ports are open, firewall properly configured, etc.).
If I’m mistaken about Stellarium plugins on mobile, please let me know and I’ll see what I can do.