I've been working on a bluetooth only ios and android app for a few months now. Been through lots of different ways to test. I ran multiple real phones from my macbook. I wrote a golang program using github.com/go-ble/ble that actually works and connects from the macbook to a phone. But in the end to really get the level of testing I needed I started:

https://github.com/andrewarrow/auraphone-blue

Which is a 100% go program but it has a "swift" package with cb_central_manager.go, cb_peripheral_manager.go, and cb_peripheral.go. And a "kotlin" package with bluetooth_device.go, bluetooth_gatt.go and bluetooth_manager.go. These simulate the real ios and android bluetooth stacks with all their subtle differences.

Using go's fyne GUI I made the actual phone "apps" and can run many android phones and many iphones. The filesystem is used to write data "down the wire" or "over the air" since this is bluetooth. Screenshot of it running:

https://i.imgur.com/Io3OZ5x.png

To test complex scenarios like 7 iphones and 4 androids all running at the same time I run this gui and keep fine tuning the logic and fixing all the edge cases. Then I move this logic from go back to real kotlin and swift for the real apps. The ios app is live in the app store:

https://apps.apple.com/us/app/auraphone/id6752836343

What do you think of this approach for testing?