A developer can use the app to simulate a BLE Peripheral with one of three
services:
* Battery Service
* Heart Rate Service
* Health Thermometer Service
The developer can use the new Web Bluetooth features to connect to the app
to Read and Write Characteristics, Subscribe to Notifications for when the
Characteristics change, and Read and Write Descriptors.
From the app a developer can set the characteristics' values, send
notifications and disconnect.