Google Analytics is a free web analytics service that tracks and reports website traffic.
jQuery plugin for seeing if the images are loaded.
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.
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.