If you don't mind the lack of polish I've been using Jami for secure communication and even file sharing and I've gotten a couple lay people set up and running

If you don't mind the lack of polish I've been using Jami for secure communication and even file sharing and I've gotten a couple lay people set up and running without much trouble. Set up is pretty easy. They don't even need you to give them an email address, but it's different. It's not going to look or act like Signal. What I loved about Signal on mobile was how it handled both encrypted messaging and plain old SMS/MMS in the same app and I don't have a real alternative for that.