First thing that came to mind is using Nostr as a way to seed/sync settings when setting up a new device with Omarchy.

https://carlsfriends.net/source.html

The interoperability is also a cherry on top of an app in my eyes, not a leading feature itself. It works well as a secondary thing to discover after using an app for a while, so making people be aware of it doesn't add much value unless you're explicity looking for something with interop in the first place. It might just serve to confuse users with needing to learn about Nostr if it's front and center.

Current longform clients are clunky for my preferences to use, but I've been meaning to turn my website into a Nostr-backed site, so natively going forward they will be posted on Nostr when I publish them.