Who uses an NFC chip for a "Trusted Device"?

[lgtomoto]

I like and use the on-body detection and BT as trusted agents to keep the phone unlocked. They both work reasonably well.
Now I want to try the NFC as a trusted device. Does anyone have it set up? I'm trying to figure out what I need for a chip or what device has a chip - something like this from eBay?10x NFC Smart Tag Adhesive Label Sticker 1152 Bits for Samsung NTAG203 Universal | eBay

 

[max_vo97]

i use some of them @home with my nexus 5x and it works pretty well!

 

[dmark44]

Curious how it works as a trusted device. Do you keep the tag behind the phone with a case it something?

 

[lgtomoto]

Tap the back of the phone to the chip which is not on the phone but somewhere like say, your desk. The phone has to have the NFC feature enabled.