Flohmarkt, which means “flea market” in German, is a “federated decentral classified ad software using activitypub” aka Facebook Marketplace clone.

Had this pointed out to me via @blaine, as we were chatting about serving real local / regional needs with Fediverse tools.

Many area have Buy Local and other Facebook Groups and Marketplace where a huge amount of community work gets done.

This isn’t the answer as just a piece of tech, but really looking at what is being used and will need to have similar functionality to really be adopted.