allow others to be invited to a 1-on-1, for a group chat
Amit Wason commented
I guess creating a invite only Flowdock is good as it keeps the conversations together, but quite often I'll want to have a temporary chat with a few people and then not need to reference that again. Creating a Flowdock for a few combinations of people and then deleting it seems a bit less intuitive that creating a private group chat.
AdminVille Saarinen (Admin, Flowdock) commented
Flows can be open to the whole organization or invite-only, the latter allowing you to have private group conversations.
I'm sur[prised that this hasn't gained more traction. Currently there is no way to have private group conversations within Flowdock, which means using additional software, such as email or Hangouts.
After having trialled Glip, this was a well-used feature by my team. We found some groups used quite regularly, based around interests and skill base.