Shrink for Github - A macOS app for your Github issues
jtrac - JTrac is an open source and highly customizable issue-tracking web-application written in Java.
GitHub Reader - A quick way to browse GitHub issues and pull requests.
asitrack – Assisted Issue Tracking - Assisted Issue Tracking is an inclusive bug and issue tracking software that comes with a lot of customization and provides you with a simple way to add custom fields and dropdowns.
Codetree - You can manage your entire development process through GitHub.
16bugs - 16bugs is an all-in-one bug tracking software that makes it easier for you to manage all sorts of bugs in performance with the simple interface; ultimately, you will be more productive for sure.