This looks like a sensible way to detect if the user is offline, and provide appropriate feedback, like making certain links or forms inactive.
Jason talks through the service worker strategy for his company website.
Jason looks at the business reasons for and against building progressive web apps. In short, there’s everything to gain and nothing to lose.
Seriously, why would you not add a Service Worker and a manifest file to your site? (assuming you’re already on HTTPS)
I want one! An ambient signifier (in lamp form) to let you know when the ISS is flying overhead. Geekgasm!