An app that was supposed to be some kind of declarative connector between two services, one that sent webhooks and the other that accepted HTTP requests of any kind. You would proxy and transform the webhooks using RequestHub and create a new request to the other service using that data.
The transformations were declared in the almighty jq language.
It worked and had other functions planned for the future, but I guess it was too arcane, even I was confused by it sometimes.
Also it was very prone to spam (involuntary) attacks like some that did happen. Maybe it would work better in a world of anonymous satoshi payments.
Later I tried to revive it as a Trello Power-Up that would create comments on cards automatically according to some transformation rules and webhooks received.