Gitslash - Autopopulate your Github Activity Chart
GHuser - Better GitHub profiles for everyone
Sweetjab - Sweetjab combines your issues and pull requests from GitHub, into a single page, to easily prioritize and delegate
Octohunt - Search to find developers in your city on Github.
GitHub Notion Sync - Synchronize your GitHub issues with Notion
GitHub Visualizer - Enter user/repo and see the project visually