GitKraken
GitKraken is a cross platform Git GUI for Windows, Mac and Linux. And it's damn awesome! I have been using this amazing piece of software since 2014 and have seen their great community grow and flourish on Slack. (Look for me there as Nexxuz.) Ever since they started up their Ambassador Program I have been a part of it as well. If you would like to try it out please feel free to use my link to sign up for a free account!
The Command Line
$ gitkraken --help

Options:
-d, --diagnostic-level, --log-level Override in-app logging level. The available values are STANDARD, EXTENDED, and SILLY
-e, --encoded-uri Encoded URI (scheme) handler; takes a gitkraken:// URI that has been URI-encoded. Overrides -p and -u.
-h, --help Print this usage message.
-l, --log-file Log all output to file.
-n, --nexxuz Nothing to see here...
-p, --path Open the repository specified by path
-u, --uri URI (scheme) handler; takes a gitkraken:// URI. Overrides -p. GitKraken URIs start with a directive, such as "repo". Example: gitkraken://repo/home/me/proj
-v, --version Print the version.
-z, --performance Run performance timings
Hidden CLI options
Options:
--disable-gpu