Google Analytics is a free web analytics service that tracks and reports website traffic.
Moment.js is a free and open-source JavaScript library that removes the need to use the native JavaScript Date object directly.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Progressive Web Apps (PWAs) are web apps built and enhanced with modern APIs to deliver enhanced capabilities, reliability, and installability while reaching anyone, anywhere, on any device, all with a single codebase.
A modest JavaScript framework for the HTML you already have.
Stripe offers online payment processing for internet businesses as well as fraud prevention, invoicing and subscription management.