Zenkit is really great! To expand what Peter said about the different views, you have items (think card in Trello) and they can have unlimited propertied (think Priority, Who it's assigned to, time estimate, due date, product area, whatever). With a click you can have the columns in your Trello/Kanban board be Priority, with vertical sorting by time estimate (for example). Another click and the cards will be reshuffled so each column is a team member and the Priority is the vertical sort. I mostly live in the Kanban boards, but I like being able to play with a Mind Map or Calendar when I need a different type of visualization to plan. Oh, you can also filter in any view!