Running this app, it's downloading about 1kb/s from push.lightstreamer.com, is that expected behaviour...?

Yeah that'd be the telemetry stream, probably specifically the new telemetry status & timestamp subscription that got added in 0.2, it gets updated maaaaaany times per second. Unfortunately it's a push and not a pull model stream so I'm not quite sure if there's any "clean" way for the app to throttle the incoming data except eg. periodically just unsubscribe from the very chatty status subscription.

Just to be sure, you mean telemetry in the sense of "retrieve latest ISS " telemetry, or "evil marketing 101 phone-home" telemetry...?

Evil marketing 101 phone-home telemetry would be going in the other direction.

So I guess in effect you're sort of getting the ISS's phone-home telemetry?

yes of course. If you go to https://iss-mimic.github.io/Mimic/ you can see the websocket to `wss://push.lightstreamer.com/lightstreamer` being opened and the stream of events. That provides a stream of ALL ISS telemetry data and this app is only making use of the urine tank data.

Next version could take the streamed data and convert it into tones. Listen to the stream. :)