I think the thread title is confusing and isn't highlighting the real news.
The story here is
checking in via A MOBILE APP
We all have cellphones here I assume. Imagine you don't have online for whatever lame fukk reason. You probably still have a cellphone that can connect to the internet. Your app will sync with your xbox one, validate it, then you can continue to game offline if that is how your punk ass wanna game
The whole friends connection is one of two things. 1.) When you at a friends house, if you don't have XBL you can still get online via your friends connection which is how Xbox 360 works as well. The other thing he could be referring to is how you can use a friends phone to use the app to validate your xbox. You can do that as well. Any other questions, holla @ ya boi