Hi, jumping straight to the point.
I understand that ServiceWorkers aren't yet supported on iOS, and as such, not available for chrome on iOS either. However, when testing on an iPhone, Notes works when I turn on airplane mode, meaning that it does in fact work offline. How is this possible? I understand that you're using Jake Archibald's cache-polyfill, but with the way your code is written, this shouldn't even be included (since the inclusion only happens if service workers are available on the navigator).
Therefore, in order to try and better understand this black magic, I decided to clone your repo and upload a version to surge.sh here. However, much to my surprise, this did not work offline!
Could you be kind enough to give me a very quick explanation of how Notes works offline without ServiceWorkers? Thanks.