Progressive Web Apps

Future of the apps. Use an app right from the browser, add to homescreen if you want. The browser is the new app store.

Requirements

HTTPS - Content has to be loaded over HTTPS.
Service Workers - The app has to use a Service Worker in order to function offline.
Manifest file - Name, icons, splash screen, etc.

Perks

Web Push Notifications - The browser does not need to be open, because Service Workers can reply to requests.