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.

GitHub Polls - Polls for GitHub issues and readme

Asana - Asana project management is an effort to re-imagine how we work together, through modern productivity software. Fast and versatile, Asana helps individuals and groups get more done.

Octotree - Github on steroids

Basecamp - A simple and elegant project management system.

Neat.run - Neat puts SaaS notifications in your menu bar. Streamline your code review and ship with ease. Preview, triage, and jump to issues in one click or keystroke.