I have a off topic question.
How have you reused your old phone? I've seen some typical lists on the web - but nothing impressive given how powerful these small computers are.
I use it as a surveillance camera with a free Android app that streams the picture from the camera as an MJPEG using a built in HTTP server. It's pretty nice, I forwarded the ports on my modem and now I can see what's happening in my home from anywhere in the world :)
I do the same with an old iPhone running AirBeam. Very handy and much easier to deal with than some poorly secured IoT camera or DVR with broken security