The direction I took was to start making a Kivy app that connects to an LLM API at home via OpenVPN. I have Ooba and LLama.cpp API servers that I can point the android app to. So, works on old or new phones and is the speed of the server.
The downsides are, you have to have a static IP address or DDNS to connect a VPN to. And cell reception can cause issues.
I have a static to my house, but a person could have the API server be in the cloud with a static IP, if you were to do things similarly.
🤔 hmmm… I have some ideas to test…