It would be lieing if I told I used it and in respect to Github's own software, that being the website and/or the client application, I found it worse. But in my first comment, which is simply «It's not.», I cannot see any indications of such statement. And I back what I state with my actual comment. On the website there is no link to information about the application, no documentation, no videos, no blog posts, nothing. Instead, I, and the software's target audience, are users of the Github.com already, and we know how to use github.com already, there is a plethora of docs, wikis, blog posts, videos which help us on using it on the web. Plus, the software is a third-party client to a service that already offers an official client. Out of this situation, the most obvious inference is that sticking to the website and/or the official application is better that using the OP's linked one. No lieing here, just reasoning.
If there was any sort of documentation or anything, a link to source on github, an end-user support possibility better than a twitter account that follows popular tech-news websites and tech celebs, I might have thought that it is promising and worth a try. But as it stands, no, it doesn't make me «step into the shop».