HacknPlan simplifies the organization of a game development project and makes the team productive. It brings a dynamic game design document builder and an agile project management system together to provide a streamlined and efficient tool that covers the full planning workflow of a game development team.
The UI is a bit cluttered, but overall is a very useful tool for game developers. It allows you to reference your Game Design decisions from what they call "Game Design Model" (which I love, Game Design Documents are outdated) from agile tickets.
