Check out this post for the latest... https://gbatemp.net/threads/atgames-sega-flashback-2018-edition-is-out-in-the-wild.522990/post-8446618
Also the Game Manager really helps with setting up the games with the interface...
Hello, I have the megadrive flashback 2018 edition, can you tell me which is the latest version for the custom firmware and a link to download it in case i have older one.