Discord

Discord is an app initially designed for video gaming communities that allows users to communicate via text, image, video and audio in a chat channel.

It started to be used in fandom around 2017 in a way paralleling the old style of communities in Livejournal or on messageboards, with a moderator and set of internal rules. Users join a server, which will focus on a specific interest in the fandom, or be used to run fanwork challenges or other fandom projects. Usage increased following the change to the terms of service at Tumblr.