Discord is an audio and visual chat platform used originally by gamers but it is a great way for anyone to set up a communications network. When I was first on steemit, I used discord for communicating wth the "busy boys" but, I am on an old iPad now and busy does not like to show up/load up on it so I am now using steemit exclusively.
I found it to be very easy to use and it's a great way to message with people on steemit as, for some reason, we don't have a message system built into it.
Quora has a simple message interface and it would be amazing to have one with muse as well.
I have a few friends from around the world on there now because of the message system.
E-GO 2018