OpenHub for GitHub - Fast and concise, open-source GitHub client app.
Gitify - GitHub Notifications on your desktop.
Nullboard - Minimalist locally-stored kanban board / task list manager.
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.
Brisqi - Offline-first personal Kanban app
Meteorite - Smarter GitHub notifications.