Interesting. It looks like "Unrestricted Web Access" is what causes it. Chrome is in the same boat, but for some reason Facebook and Twitter don't have the same requirements even though they allow access to web content via links.
I'm not sure if this would work for your app, but maybe you could restrict access to just github.com? I'd also second a video or something more insightful on the landing page of the app's website.
Running my site through their validators said too many redirects occurred.