Warning: the company that made these shut down their servers, so you can only use these if you already had their app installed and logged in. (You can only find your current tags, or add new ones.)
That said, they do appear to be roughly standards compliant so it should be possible to use them with other apps, and I’ve used one or two, but nothing super easy and an obvious win to suggest.
If anyone wants to reflash the nrf52811 micro on these, hit me up for the debug pinout 