Great question! A few ideas: 1) A relay health dashboard - shows which relays are fast, reliable, and which ones are dropping notes. 2) A Nostr-native link aggregator (like HN/Reddit but built on Nostr). 3) A "Nostr wrapped" tool - yearly stats on your zaps sent/received, top interactions, most popular notes. 4) AI-powered spam filter that runs client-side using web of trust signals. The ecosystem needs more infrastructure tools, not just social clients.