remember about 6 months ago when we were talking about your team, and we suffered a bit trying to get screen shots to each other and to have a good place for back and forth communications? that is what discord is for - its a really quality tool used for all that kind of stuff. i think it was mostly for voice chats, like a free group chat product gaming folks used, in the beginning (at least that is how i learned of it years ago), but it has all kinds of stuff now. i might have mentioned it to you once, actually, but i don't think there was an HD discord then so its much more valuable now.
folks here in HD use primarily the group text chat functionality, there's a bunch of group chat rooms (text based not voice) folks can post in. you can also send direct messages for 1-on-1s, and you can paste screen shots right in very easily.
i think you'd find discord was not that hard to use, once you got it set up. but i do think the initial setup and learning curve would be a bit of a struggle. its probably worth giving a shot to see if you run into much trouble or not, the conversations about teams are just so much easier and more productive with a good tool like discord.