there is lightning based https://beta.predyx.com/ and https://delphi.market/ by nostr:nprofile1qyt8wumn8ghj7cnfw33k76twv4ezuum0vd5kzmqpr4mhxue69uhkummnw3ez6ur4vgh8wetvd3hhyer9wghxuet5qqsdr8lv2sp86ztsv4yz9q9wz7ng6zk40u84cta8fcj08kamrek9f9gmaszu0 tho not sure if he still actively works on it