AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.
Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.
Facebook pixel is an analytics tool that allows you to measure the effectiveness of your advertising.
GetResponse is an email marketing app that allows you to create a mailing list and capture data onto it.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.