Pwa
From Wiki2
Progressive Web Apps
https://developers.google.com/web/fundamentals/getting-started/codelabs/your-first-pwapp/
https://www.smashingmagazine.com/2016/08/a-beginners-guide-to-progressive-web-apps/
webworkers service workers
https://developers.google.com/web/fundamentals/getting-started/primers/service-workers