This looks quite interesting as an online Kanban board. Spotted this morning whilst reading the morning brew blog. I am not convinced that you can emulate a Kanban board successfully but this seems a nice little solution for organising a group of tasks.
In a similar manner to Pivotal you can Label tasks but I don't think it's quite as extensive as Pivotal. I think one of these tools would be really nice if you could tie them up with a git commit or so when someone picks it up to QA then can easily see the changes as part of the card.
via >> http://jesseliberty.com/2013/10/25/two-dozen-insanely-essential-programmer-utilities >> http://blog.cwa.me.uk/