Web App + Nostr login + Lightning payment = Keychat Mini App.

When you open a Mini App in Keychat and choose Extension login, Keychat will pop up a list of IDs for you to select which one to use to log in.

When you pay a Lightning invoice inside the Mini App, Keychat will automatically invoke the Keychat wallet to complete the payment.

In addition, you can add your favorite Mini Apps to Favorites, so next time you can open them directly from the browser home page.