Shameless plug : I'm working on https://cartes.app, a Web OpenStreetMap app.

Far less difficult as coding for an old OS obviously, but still a challenge !

The Web has plenty of potential, but constraints too, mostly because of dominant actors, such as Apple that hid the PWA install button... Or Firefox not having any install banner, whereas chrome does.

Can't post it yet as a proper subject, it can't handle top page load.