Does anyone know if there’s a way to make a ringing iPhone a trigger for an automation?
Assume you are using the HA Companion app, if so here’s how I get “ringing/in use” (Android, but it can’t be much different!)
{{ is_state("sensor.<your iphone>_phone_state","ringing") or is_state("sensor.<your iphone>_phone_state","offhook") }}
Trigger is “When a template triggers”
Iphones doesnt have ring detection.
Of course, why would an Apple phone be conformist 
Not implemented in any release yet, but am implementing and testing this locally with our local Bluetooth iPhone/iPad/Apple Watch device tracker with unlocked property implementation, but there are still a few kinks to sort out and decide how to best define things.