When you're creating a presentation you regularly need to see a preview of your work. It's hard to commit/push for each review. Is there any other way for seeing the final output of GitPitch?
There is a way to make changes and preview those changes without having to push every change to your remote git repo. The approach is detailed on the GitPitch Wiki, see the Developing / Testing Locally page.
As that particular Wiki page states:
Sometimes you may want to develop some or even most of the content for you presentation locally and then push the final PITCHME.md when you are done. While there is no dedicated tool for GitPitch that supports this kind of develop-then-preview workflow there is a simple approach that may be useful for some.