Wekan is an open-source and collaborative kanban board application.

Whether you’re maintaining a personal todo list, planning your holidays with
some friends, or working in a team on your next revolutionary idea, Kanban
boards are an unbeatable tool to keep your things organized. They give you a
visual overview of the current state of your project, and make you productive by
allowing you to focus on the few items that matter the most.

Wekan implements all the goodness of kanban board in an open-source software
that is free to use and modify. It supports most features you would expect of it
including a real-time user interface, cards comments, member assignations,
customizable labels, filtered views, and more.

Wekan supports Sandstorm as a first-class platform and integrates with its
sharing model for seamless collaboration.