We've been using it internally as a debugging tool for the Geotrigger Service (https://developers.arcgis.com/en/features/geotrigger-service...), which is a geofencing API & SDK. We can make a mobile device spit out location updates and see them mapped in real time, see what the headers and content of the POST are, and figure out what needs tweaking. We wanted to generalize it as a free service to allow others to do the same and also explore how else it could be used.
Hmm, strange symptoms. I haven't any issues like this. I've been using github pages + CNAME + gh-pages as project pages together for over a year without any issues whatsoever. Didn't have to worry about submodules either. Not sure why you're into these issues, kecebongsoft. I've used Jekyll as well as plain old html. I'm sorry you've had issues like this but I wouldn't discourage people from trying it either.
https://github.com/moose-team/friends/issues