The best part about shared cockpit is helping each other reduce workload while flying on online networks.
The hoster can connect to vPilot as they normally would.
The people joining the host should have the same callsign, but with a letter after the callsign. They should also tick on observer mode.
Connecting with a letter after the callsign in observer mode
You can have as many people flying with you as you want!
The hoster can connect to IVAO via the Altitude client as they normally would.
The people joining the host should have the same callsign, but with the letter M after the callsign. They should also connect as an observer.
The official IVAO documentation states that the observer should connect with a letter M, but doesn't explicitly state if more than two people can share an aircraft. I haven't tried it myself, but it should work similarly to vPilot.