Bump for Trello. I use it to manage my team (who work remotely) and personal life, too. We use it for vacations, long-tern house projects (gardening, building things, etc.)

I've tried Slack in a few different contexts and have always found that the chat-based interface encouraged users to do just that: chat.

A combo of Trello + email work better for keeping communication focused on the product/project, in my experience.