Who is receiving or has been receiving?

Google Prop Map on WSPR net provides an idea who is or has been reporting, in particular when one is using the magnification feature of
the Prop Map.

Of course reporting is by no means the same as receiving!

This indicates another reason for a positive indication of who is in the
receive mode and is participating as a reporting station.

Checking in and out to some sort of list or roster would help here.

When starting up WSPR, the program could send a signal to a central
point:
Station is in receive mode AND download mode for frequency
XXX.
When WSPR is terminated another signal is sent as station is not longer active as a receiving station.