Codegiant - Codegiant - Issue tracking, git repositories, continuous integration and documentation in a single platform.
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
GoRetro - a free retrospective tool for your Agile sprints
Hygger - Hygger - is an Agile project management tool with built-in prioritization.
Scrumpy - A simple, beautiful and agile project management software
Nifty - Manage projects, work, and communications in one place.