Trello

Trello is a kanban board tool: cards move across columns representing stages of work, and the whole model is visible at a glance without any setup.

That simplicity is both its strength and its limit — it is quick to adopt for a small project and quickly outgrown by teams needing dependencies, workload views or reporting.

Its free tier is generous enough for personal and small-team use, and Power-Ups add automation and integrations when needed.