Get Social Media (Facebook, Twitter, YouTube, Google+) Followers Count Using PHP

Each social media provides their own widget to display followers count, but their user interfaces are different and so much javascript in the code. So I decided to get the count on server side using PHP, cache it and show it as I want. This post explains to get Twitter followers, Facebook fans, YouTube subscribers and Google+ page/profile followers count, to cache the results and generate HTML to display them.