bartscherer:
I'm reasonably certain I can achieve what I want with a garden variety HC-05 Bluetooth module and an Android Phone.
Probably correct. What you are talking about is plain-vanilla data streams, two-way, SPP protocol.
But I've seen references to iPhones and other Apple devices requiring Bluetooth "BLE" and a different chip (HM-10?).
Correct. The bottom line is that HC-05 is incompatible with iStuff.
nice if it could work with laptops of either flavor, but maybe that's a different subject?
No, just better understanding. As far as I'm aware, all laptops are MacOS and OK with HC-05. It is only IOS (phones and tablets) that are the problem.
BLE is a different ballgame compared with HC-05 and, unless you are happy to play within its rules, seems to be more trouble than it is worth. It is probably easier to conclude that anybody who can afford an iPhone can afford an Android to do the real work, and leave it at that.