Near Field Communication (NFC) is solid, industrial connectivity technology, but it was late to the iPhone.

Sure it powered Apple Pay, but for a long time that was all. Apple didn't allow other apps to use it. Apple wanted to stack the deck in favor of iBeacon technology.

Then in late 2017, around the time I was evaluating my connectivity options, Apple relented and enabled NFC on the iPhone.

It was still playing catch-up with the cool kids, but two things in particular were appealing about NFC: 

1. The technology, which made it possible for the tiny NFC receivers -- which looked like thin, tiny metal coils -- to just sit there, passively, not using any energy, until they were "excited" by a nearby reader of some kind -- for example a phone. Elegant. 
2. The widespread use of NFC in unsexy, pragmatic applications. Office entry cards, for example. 

Check out NFC World for the latest everyday applications. 

So I added NFC to the control panel.  

A safe decision since there were plenty of apps, for both Android and, belatedly, iPhone.