The Web Bluetooth
API lets websites discover and communicate with devices over the
Bluetooth 4 wireless standard using the Generic Attribute Profile (GATT). It is
currently partially implemented in Android M, Chrome OS, Linux, and Mac.
This sample illustrates the use of the Web Bluetooth API to read and write the standardized Alert Level characteristic from a nearby Bluetooth
Device used to expose the current link loss alert level that determines how the
device alerts when the link is lost. You may want to try this demo with the nRF
Connect for Mobile App from the Google
Play Store and its pre-configured Link Loss service, and check out the Link Loss (Promises) sample.