Progress Web App

I've played with the Progressive Web App info in the web core manual, and with the PWA demo. I've also clicked this link: https://www.tmssoftware.com/calc/index.html. I can't make Chrome or Firefox ask to place an icon on the desktop.



In the Chrome desktop browser, the menu item (right-top menu) "Install Calculator..." will be added.

On Chrome on Android, a popup notification is shown.