Google Analytics is a free web analytics service that tracks and reports website traffic.
Google Tag Manager is a tag management system (TMS) that allows you to quickly and easily update measurement codes and related code fragments collectively known as tags on your website or mobile app.
Open Graph is a protocol that is used to integrate any web page into the social graph.
TablePress is a free and open source plugin for the WordPress publishing platform. It enables you to create and manage tables on your website, without any coding knowledge.