Gitscout - A beautiful Github Issues experience for macOS
Zube - Project management for developers.
Zokyo - GitHub Chrome Extension to track and manage issues
ZenHub - ZenHub is how the world's best software teams work together. Trusted by NASA, Docker, and Rackspace. Start free today!
GitHub Reader - A quick way to browse GitHub issues and pull requests.
Nifty - Manage projects, work, and communications in one place.