If you’re reading fan translations then BakaUpdates is what I would recommend using since it follows the release of scanlators. I believe many scanlators themselves are using some form of email blast or RSS announcement of new chapters as well. I don’t doubt some use something like Discord to announce releases, but that’s not a preferred method for me to hear about releases. You’re welcome!
Gimp has always been such a lifesaver for me. I’m glad to see it still has been getting improvements!