I think the best use case I’ve seen for nfc tags are periodic reminder reset. Place a nfc tag near your filter register then when you change your hvac filter, scanning the tag records the date which can then be used to send notifications when it’s time to change the filters again.
I set up two tags that trigger the Bedtime routine and taped one to the side of my wife and I's bedside tables. I much prefer scanning the tag over bothering with my phone or yelling at Google (until I give up and do it on my phone anyways).
I also set up a few medication reminder tags for my wife. Reminder triggers once an hour until she taps the tag on the pill bottle. Very handy with medications on different schedules.
The spouse acceptance factor is huge. Nothing for her to remember.
Do you really always have your phone on you when you're at home? When I'm outside then yes I have it in my pocket, but at home it's either charging or just on the table in a different room.
This is why they aren't useful around the house for me. I will say that I regularly use the one glued to the outside trim of my garage door (white on white trim so completely hidden dot) to open and close my garage when out biking with the family. That's actually really useful.
I am using iOS. The ones I bought are very generic, I will try to find an Amazon link and report back. There’s very little difference between versions so I think just about any would work with both type!
I have one inconspicuously hidden under a sticker that will unlock one of my smart locks. Needing to unlock my phone is what prevents me from using it that often, though.
It is fun to use it when friends/family are around, and see them go "Whaaaat?!"
HA handles them really well actually. You can flash them directly from the HA app, and as long as NFC is turned on on the phone, you can just scan them and execute whatever automation they're tied to without opening the app. You can buy a 50 pack for like $15 on amazon/aliexpress.
Also if you have a 3D printer, you can slip them into your prints while printing and have them fully sealed inside the object (I have a giant 3D printed house key that has our wifi login embedded in it)
I haven't tried HA with NFC tags yet, but if I tap an NFC tag with my phone, it'll show a list of app that can be launched to handle the tag. The phone need to be unlocked though.
My favourite use case:
I have an automation that wakes me up with light sunrise effect. NFC tag on the wall near bed "snoozes" light alarm for 20 minutes.
We have several Nintendo Amiibos that work perfectly as tags. One (Bowser) toggles our air conditioner. Another (Mario) sets a movie scene and the last one (Yoshi) turns all the lights to bright in our living area. I've also added some small stickers near our beds to toggle the lights. It's fun finding another use for the amiibos (besides playing Tears of the Kingdom).
I set up an alert every 4 hrs that reminds me that my cats litter hasn't been cleaned. When i finally do it i scan a NFC tag to let my HA know that the litter is clean