PlanITpoker - PlanITpoker is a cool on-line planning poker app that helps Agile project teams estimate projects easily.
Kanboard - Kanboard is a free and open source Kanban project management software.
Taiga - Project management platform for agile developers & designers
Excalidraw - Excalidraw is a whiteboard tool that lets you easily sketch diagrams that have a hand-drawn feel to them.
Craft.io - All-in-one product management software for entire product lifecycle
Kinopio - Thinking canvas for mind mapping, brainstorming, and moodboards