You know who published it. It's the fdroid devs. Fdroid follows very much the old Linux repository philophosy where the owner of the repo acts as a middleman, providing the central layer of trust. You don't have to trust the developers because the distributor has done their due diligence and checked it. That's why fdroid takes a couple of days to push updates. They are doing some basic quality control first.
This model made a lot of sense in the world of traditional Linux packaging, where every obscure distribution has their own package format and developers couldn't possibly be expected to support all of these. It makes less sense on Android (or in a word where flatpak exists for that matter).