I like that distinction re BLE/NFC. Could be useful for a makerspace, where you want to know who is present and then you also need to check in on the machines you're using.
I was assuming everyone who wanted to use the interface could have an app that would advertise, maybe a conference app or something. Not sure exactly. I feel like the technology is almost there.
Maybe more useful in agriculture– put a Tile on each of a herd of cows and then you know whether any are missing at the end of the day?