Google Analytics is a free web analytics service that tracks and reports website traffic.
Google Maps is a web mapping service. It offers satellite imagery, aerial photography, street maps, 360° interactive panoramic views of streets, real-time traffic conditions, and route planning for traveling by foot, car, bicycle and air, or public transportation.
Kevel (formerly Adzerk) is a developer of ad-serving APIs to help developers build server-side ad platforms.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Stripe offers online payment processing for internet businesses as well as fraud prevention, invoicing and subscription management.