A stand alone clone of Bopple. Which is a generic app that coffee shops can use to allow customers to place an order and that creates a user account so that users can get loyalty rewards.

If it was built on nostr it could automatically install nos2x to store their private key and set them up on nostr.

The benefit to the restaurant is that they would be connected with their users on the nostr protocol, not just while they are using the app.