Trello does not offer the permissions, reporting and customisations that Jira allows, but it is very quick to get started with. It should be said that the cards/board metaphor also exists in Jira on Kanban and Scrum boards, but for lightweight general projects where the emphasis is on ease of use rather than reporting, Trello is worth looking at. It is a tool that can be used for home projects, for example. Both Jira and Trello have free tiers available.