git-presenter isn't design to show you the code as such. It is intended that you would use your normal text editor to walk through the code during a presentation in a user group or conference type setting. The purpose is purely to stop you needing to live code when doing code heavy presentations.
My workflow with it is usually start in the editor, explain a bit of code, switch to the termainal (or if i'm using vim i'll just execute the next command in there) then explain the next bit of code and so on and so on.
What are you expecting/wanting it to actually do. I am very open to other ways of using git-presenter and adding it into later releases.