This is an Bluetooth Low Energy beacon that can be worn and used as a presence beacon for Happy Bubbles presence detectors. It lasts about a month from a single coin-cell battery and can be configured with the following mobile apps:
To use it, turn it on by holding down one of the sides that is a button. After a couple of seconds, a blue LED should turn on.
When you change parameters, soft-reboot the beacon via the app menu option to save/persist the changed parameters and make sure to include the default password: minew123