@Ambraven There are some free OS inpired by Android, like Replicant which is guaranted to be free/open-source and not spying on you, but very limited for everything that is not basic-phone-stuff. And Cyanogen/Lineage which is more of a "clean install of Android without pre-installed apps and Google apps" but it's still Android. I don't know if that's what you're looking for.