I'm currently building an app for instant messaging (similar to whatsapp).. in my requirements doc I'm trying to define the roles. Like in any messaging app, there is the person who's currently using the app (i thought of calling them the "sender" but that's not accurate.. because obviously the person using the app may receive messages) and then there are the "other" people. I don't think "other" really makes much sense.
Any suggestions or industry known practices for this?
update
i winded using "peers".. here is a sample gherkin scenario where I'm using this:
Scenario C: main messaging page - create new message
Given user wants to send a new message
when user clicks on compose button
Then a list menu shows up, listing all the peers
When user taps on one peer on the list
Then a new chat window shows up
And they can both start chatting