Yes: https://developer.mozilla.org/en-US/docs/Web/Progressive_web...
I tested just now in Firefox with an app from https://appsco.pe and it does indeed work!
I can do the same with the Android version of Brave.
> If you install Firefox it uses Gecko but still has native app look feel?
That depends on your definition. Making an app _feel_ native is a matter of implementation. But the opposite is also true: A native app is free to feel non-native if the app creator makes it that way.
The app does show as a distinct entry in the app switcher, but still has a Firefox icon when I tested it just now.
I tested just now in firefox with an app from https://appsco.pe and it just...opened a browser tab with the website.
So I understand a PWA is just a website but isn't the whole point to have a dedicated window/card for it?
It looks like appsco.pe has some incorrect entries in its list of PWA.
So if you install a PWA from Firefox it runs in Firefox and from Chrome it runs in Chrome similar to desktops. Looking at it this way I could see Apple doing something similar with less effort than trying to standardize a web view API and have PWA use the "system default browser".
https://web.dev/learn/pwa/tools-and-debug#using_physical_dev... at "Firefox Remote Debugging" says there's a way to debug Firefox for Android PWAs.
So I'm fairly sure the PWA is running using Firefox for Android.
I also never accepted the terms and conditions for Chrome on this phone.
https://developer.mozilla.org/en-US/docs/Web/Progressive_web...