Not on Nostr to my knowledge. But there is one in the @Club Orange app. Besides the possibility to connect and chatting to any merchant there, it has a really cool feature of targeting merchants and any other users, via geozapping or other forms of zapping. This is sometimes referred to as zapvertising. Imagine sending a couple of sats with a message, image and/or link to a targeted audience in your city, region, country, etc.. This is already possible.