SourceTree - Mac and Windows client for Mercurial and Git.
GitKraken - The intuitive, fast, and beautiful cross-platform Git client.
TortoiseGit - TortoiseGit is an easy to use client for the Git distributed revision control system.
GitHub Desktop - GitHub Desktop is a seamless way to contribute to projects on GitHub and GitHub Enterprise.
Sublime Merge - Fast git client with integrated merge tool from the makers of Sublime Text
Fork - Fast and Friendly Git Client for Mac