Workbox : JavaScript Libraries for adding offline support to web apps.
sw-precache : Service Worker Precache is a module for generating a service worker that precaches resources. The module can be used in JavaScript-based build scripts...
sw-toolbox : A collection of service worker tools for offlining runtime requests
schema.org : This site provides a collection of schemas that webmasters can use to markup HTML pages in ways recognized by major search providers, and that can als...
