I was thinking about this project you are working on, and I thought about an app that can help you get it off the ground faster.
I’ve worked on a few projects like yours and keeping everyone on the same page was always the worst. After adding a few people to a team everyone starts putting documents everywhere and conversations bounce aimlessly between email and chat. It’s a mess.
The way we solved this issue was using Basecamp. Basecamp is a tool that helps you keep all communication in one place. It also helps you break down big projects into smaller teams or tasks. Basically, everything that you do now with Slack + Dropbox + email + calendar, you can do with Basecamp but better (also less expensive than these btw). It was a game changer for us.
If you want to take a look, sign up for a trial at basecamp.com. They don’t even ask for a credit card to try it.
I would just suggest trying it now if you can. It's much easier to switch early before everyone starts using different apps.