Free - GPL v2 or later.
Text-mode Git repo viewer.
Ranked in these QuestionsQuestion Ranking
Pro Allows you to stay in the terminal
If you prefer to do most of your development inside the terminal, changing windows to move to a GUI git client can be annoying. Since tig runs inside the terminal, that's avoided.
Pro Available in Homebrew
Can easily be installed with homebrew simply by running
brew install tig
Pro Works on any platform
Pro Vim-like bindings
Con Steeper barrier to entry as compared to a GUI solution
Since you have to get used to working in the terminal (if you are not already used to doing that) and learn the commands, it has a steeper learning curve than GUI clients which are usually more intuitive and easier to grasp.