Hi
My first PWA fiddles. In search for an easy way to plan meetings cross timezones (needed in my current job). Due to lack of better/free alternatives. And because I don’t need a big reason to try to build my own 
PWA hosted link (Firebase):
https://worldbooker-798b1.firebaseapp.com/
Nice to see it pass the Lighthouse test as a way to accomplish PWA status.
And no, it isn’t necessary very pretty to start with (icons). And many things to do.
Regards,
Tom