Two great kanban tools to try are Trello[0] and Codecks[1]. The latter is sold as a tool for game devs but there's nothing about games in it and we use it for enterprise software dev. Interestingly, kanban was invented by Toyota who used it to revolutionize their company's accuracy and productivity[2].
[0]http://trello.com
[1]http://codecks.io
[2]https://en.wikipedia.org/wiki/Kanban