We have been asked a few times, which beacons are compatible with the Physical Web app.
The Physical Web is an open source project, championed by Google, that uses Bluetooth beacons to transmit a URL. The URL can point to anything, but this is typically a web page. In theory, an app is no longer required. However until (or if ever) this is baked into operating systems, you still need an app or a web browser that’s listening for the advertised URL.
Eddystone-URL is used for the Physical Web URL. Hence any beacon that supports Eddystone can be seen in the Physical web app.