Google Analytics is a free web analytics service that tracks and reports website traffic.
Gravatar is a service for providing globally unique avatars.
MailChimp for WordPress is an email marketing plugin that enables you to build subscriber lists.
MonsterInsights is the most popular Google Analytics plugin for WordPress.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Pure CSS is a set of small, responsive CSS modules that can be used in web projects.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. Features include a plugin architecture and a template system.
WP Engine is a website hosting provider.
Yoast SEO is a search engine optimisation plugin for WordPress and other platforms.