I use a spare smartphone with no SIM card as a navigation tool in my car. This works fine with offline maps, but I can't use things like Waze. I also have an iPhone which I carry around with me, which does have a SIM card.
I wanted to know if there was a way to have the iPhone automatically start its Personal Hotspot tethering when it sees the other phone is in range via Bluetooth.
This would allow data access to the SIM-free smartphone only while I was in my car, which would be a perfect solution similar to what the Tasker app on Android can do. Perhaps something like the Workflow app would help?