Music integration would be a good one in nostr. Nostr-native tracks that show on your profile if enabled. Make for easy discovery and explore further in specialized client. 

Give creators tools to showcase their stuff and get paid in the process 💪 

Same with media gallery for artists. 

Integrated commerce in general would be amazing. 

Small specialized clients are nice. But small specialized clients connected via nostr social clients is where it’s at I think. 🧐