GITK - The GITK - Generalized Interface Tool Kit is a set of libraries, which form a (user) interface...
GitKraken - The intuitive, fast, and beautiful cross-platform Git client.
Sublime Merge - Fast git client with integrated merge tool from the makers of Sublime Text
SourceTree - Mac and Windows client for Mercurial and Git.
OctoDroid - Mobile GitHub client for Android.
Git Force - Git Force is one of the powerful tools that allow you to push changes in the commit history, making it free not to line with new or anyone in the future.