I've created a tool to show who's talking on the hub. You can see it here - https://mon.hub.emfhams.org
It's currently a work in progress, so it may malfunction or be down from time to time. Depending on the crosslink the user is keyed up on, you may only see their callsign.
The backend, known as the "Hub Events Collector" (HEC) is written in Python. It collects events, such as someone pushing the PTT from the various crosslinks and pushes them to an MQTT server. Its written in away that allows plugins so in theory it can collect from other sources and push to other destinations.
All the events are available publicly via MQTT if anyone wishes to build their own 'app' with the data.
I am not a web developer and could do with someone else picking this up, so I can spend more time on the 'back end'. Please get in touch if you would like to help out.