It's a good tool for team communication and you can separate differents subjects in to separated "flows" or channels. In addition, you can invite people to join just one channel increasing privacy for others members.
There is a possibility to integrate with external services such as e-mail (send messages to a flow inbox from your e-mail), twitter, github, confluence, jira, etc. Actually, there are a lot of options to integrate!
Single Sign-on is also available as an integration service.
Is possible to use a free version up to 5 users. If you are a non-profit organization or have a student project, they say that is possible to work with that too. In other case, you have to pay per user/month.
Flowdock is also very easy to configure. You can get it running for your company or team in a few minutes. Furthermore, almost all platforms (Windows, Linux, Mac, iOS, Android) have an app to install and there is a web version that can also be used.
Flowdock is a simple tool that delivers team chat and an inbox that integrate with external services. But its just that. If you are looking for some more robust tool, with more features and more personalizable, it may not be appropriated for you.
Other thing a little bit annoying is that a lot of links to others Flowdock sections (preferences, external services, etc) will open a new window/tab. Each click may take you to a new window and you can get lost easily. Also there isn't a quick access list to members of your organization to start a private chat. I took a while to find how to do that. The interface and usability could be better.
I also missed an app for Windows Phone.
You should try Flowdock using its free version for a small team and compare with others similar products such as Slack. Flowdock delivers team chat and collaboration features, but is not necessarily the best product. Maybe some usability problems that disturb me won't be so relevant to you.
Team collaboration, specifics communication and quick file sharing. To avoid a lot of calls during the day, a centralized platform divided in differents channels can be very helpful.