Yea. I have checked out a few nostr web app. They are not true PWA. They need the manifest file along other factors. My prototype, I intend to showcase a true PWA as well, to help nostr devs move towards that. As you can see from the screenshot. It looks and feels like a native app. 
Discussion
And there is also a service worker configuration, allowing you to have a very effective local data storage and full control over caching. This project will follow best practices and that experience will be consistent across all the website.
Ah. I have not started testing out mobile devices components with service worker.
Nostr.kiwi, you can add it into your app list and marketplace.

