I believe tig [1] and gitk [2] are the standard tools for doing this. Either the author did not know about them or he did wrote anyway as a fun project.
As someone that often works across multiple projects, I find the ability to do a recursive search through a directory of git repositories very valuable.
This is cool. Is there any tool to get some kind of interesting stats like number of commits, your commit frequency, how much code you have changed, what are your "productive hours" and things like that.