CodeStream - CodeStream helps development teams resolve issues faster, and improve code quality by streamlining code reviews inside your IDE
GitHub Visualizer - Enter user/repo and see the project visually
codebeat - Automated code review for Swift
GHuser - Better GitHub profiles for everyone
Codacy - Automatically reviews code style, security, duplication, complexity, and coverage on every change while tracking code quality throughout your sprints.
Octohunt - Search to find developers in your city on Github.