If I understand correctly, Hypatia will continue with a new maintainer and is now in the Izzy repo

Pinetta is under development: “A FOSS, federated, ActivityPub-enabled pinboard thingy, in the style of Pinterest.”. I don’t know anything else about it, but only discovered it on this list: delightful fediverse apps (“A curated list of server applications with support for the ActivityPub protocol (known as the fediverse) and related standards.”)