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.
StatCounter, a free online visitor stats tool. It offers its members the chance to grow and improve their online businesses by allowing them to monitor the number of hits to their website; the geographical location of visitors; the various pages a visitor views; keywords used to find the site plus other features.
This site uses the viewport meta tag which means the content may be optimized for mobile content.
Using this tag you can set up your web app to have an application shortcut icon added to a device's homescreen, and have the app launch in full-screen "app mode".
Open graph description entity tag
Sites who has this tag are verfied by google to use WebMaster tools