There seems to be many folders and files to upload for android apps so instead of posting my hello world app on this website, I decided to upload it on github. Here is the link for those of you who are interested in seeing the source code: https://github.com/Aion-/HelloWorldAndroid
I have yet to take a look at the documentations of the Android SDK, but I am starting to get the hang of it.
Yes, GitHub is very good for most projects. I'm actually planning to add a feature that allows you to import and sync your GitHub projects into Hawkee. The goal is to provide a place for users to discuss projects in more of a social setting.