It looked promising when I was evaluating it a few months ago, but it's limited to use with Elasticsearch 1.x, which was not going to work for us.
As the developer, I do!
Feel free to email the mailing list ([email protected]). I'd be happy to help answer any questions you might have
"ZomboDB is a Postgres extension that enables efficient full-text searching via the use of indexes backed by Elasticsearch. In order to achieve this, ZomboDB implements Postgres' Access Method API.
In practical terms, a ZomboDB index appears to Postgres as no different than a standard btree index. As such, standard SQL commands are fully supported, including SELECT, BEGIN, COMMIT, ABORT, INSERT, UPDATE, DELETE, COPY, and VACUUM."
https://github.com/zombodb/zombodb