Google Publisher Tag (GPT) is an ad tagging library with which you can dynamically build ad requests. GPT takes key details from you such as ad unit name, ad size, and custom targeting, builds the request, and displays the ad on web pages or mobile apps.
The Tweet Button is a small widget which allows visitors to share content and connect on Twitter.
This site uses the viewport meta tag which means the content may be optimized for mobile content.
Open graph description entity tag