I have two old iPads and an old iPhone in my stack.

The iPads are HomeAssistant Dashboards for me. One connects to a VNC server on the HA host, as the browser is too outdated to properly display the dashboards. The other uses the HA app, and can render just fine.

The iPhone is jailbroken, and used as an AirPlay relay server. Connected via Bluetooth to a speaker, MusicAssistant keeps the audio from the aux on my Mac Mini and the audio streaming to the iPhone in sync, creating surround sound audio.