What do I need?
- HTTPS hosting for your app
- Create a manifest.json file which needs the following set:
name
short_name
start_url
display
with a value of standalone or fullscreenicons
which includes one image set to (at least) 144×144, in png format e.g."icons": [ { "src": "/images/icon-144.png", "sizes": "144x144", "type": "image/png" } ]
- Validate the manifest file and add it to your site html
- Register a service worker
- Confirm it works offline by using chrome dev tools > Network > tick 'Offline' and refresh page