Pwa calculator is a simple test project I made, with some basic JS and PWA technology, the main purpose for the task was to learn more about how the PWA works. To make this task I follow a guide on google, I will link to the guide bellow so that you as a reader can see if you want. I will also add a link to the PWA itself so that you can see it and try it, at the moment the PWA technology is not supported by every browser so if you want the app on your device, I suggests that you use Google chrome or Chromium.
Google Workbox
https://developers.google.com/web/tools/workbox/guides/get-started
PWA
https://caniuse.com/#search=PWA
The PWA it self
https://pwa-clck.netlify.com