[toyg]

They probably used FTP while developing [5] and a lot of online chatting [6].

[5] http://fivedetails.com/flow/

[6] https://www.getflow.com/apps/

[chris_wot]

To get it done, they would have used project management [7] whilst management decided on EDI integration suites. [8]

7. https://www.getflow.com

8. http://www.flowsoftware.com

[vehementi]

Do you think they were a little bitter about Slack and probably used a competitor [9] instead?

9. https://www.flowdock.com/