First draft of the introduction

Rewrote the introduction as a usecase.

Pulled the introduction into a separate file.

This is a first draft but thought I'd get out a general idea of the introduction I had out as soon as possible.
Source? Also, lower casing of "S". Also, I'm not a fan of "computing device", sounds like many people only use it with the goal to "compute" something, while most people are not even aware or caring about the computing part. How about "For many people, their smartphones have become essential to their lives, as social activities, like chatting by means of Whatsapp or Facebook, are daily necessities."
source: http://www.nielsen.com/us/en/insights/news/2014/how-smartphones-are-changing-consumers-daily-routines-around-the-globe.html