I use Plato for testing at times. And the creator of Plato is still around though not very active lately. However new releases are not posted here, you have to go to Baskerville's GitHub page for
Plato to get the newer releases. I think the last one was 0.9.42 a couple of weeks back.
I've use the
One Click Install packages for the basic install for both KOReader and Plato and then updating both manually.