Many of us have an issue with Slack due to its centralised nature and lack of privacy. Steemit.chat is an excellent open source tool that have many possibilities to create further open or closed chat rooms within Steemit. Personally, I'd like to see the chat option integrated in to the platform itself.
Graphene is amazing btw, so undervalued, underutilised and something I'd love you to explore via bitshares.org to give us your opinion.
Loved the photo btw, we need more like that on Steemit.