https://patreon.com/joiplay and there listed https://joiplay.cyou as well
There is also discord with step-by-step guide, and explanation Google keeps rejecting market updates for weird reason like "you requested files access: we don't think it needed for your app" xD
Btw, joiplay does launch your game just fine as is.
Also, consider moving to webp from png. I am not a designer myself, but it is a hype nowadays, offering either better compression or quality, and both lossy and lossless options. And Renpy should support it, like, since 2016. But some people complain, on high compression it loses sharpness giving as they say "plastic look", instead of familiar blocky noise of old jpg-like algorithms.