I'm working on an iOS/macos nostr client called Damus. I'm thinking of a scheme using lud18 to create proof of bolt11 payments using nostr keys. This will allow you to do lightning tips over nostr in a secure way: talling tips on posts, fundraisers in a post, etc.

Excited to start implementing this soon as this may be one way to incentivize running nostr relays by donating a proportion of your lightning tips to the relays you're connected to.