"Progressive web app" template / example with cache management.
Minimum requirements for https://developers.google.com/web/progressive-web-apps/checklist.
Tested via Chrome Developer Tools > Audits. (see it on https://www.emanuelefornasier.it/pwa/ )
- Https connection (here it's forced via .htaccess)
- https://developers.google.com/web/fundamentals/primers/service-workers/
- https://www.sitepoint.com/getting-started-with-service-workers/
- https://codelabs.developers.google.com/codelabs/add-to-home-screen/#0
- https://developers.google.com/web/fundamentals/app-install-banners/
- https://stackoverflow.com/questions/34369951/how-to-get-add-to-home-screen-pop-up-on-site-open-in-mobile-browser
- https://developers.google.com/web/updates/2015/10/display-mode
- https://blog.betapage.co/how-to-add-add-to-homescreen-popup-in-web-app-99d5237fabff
- https://www.howtogeek.com/196087/how-to-add-websites-to-the-home-screen-on-any-smartphone-or-tablet/
Some code blocks and comments are copy-pasted (adapted when needed) from the links above (all credits to original authors).