For anyone that has friends that can be convinced to move off snapchat:

• it doesn’t actually delete things after the timer goes out, it just hides it from view. Sometimes the app bugs out and that data will be accessible again
• signal has stories and the same format of disappearing messages
• everything else that’s good about signal

If what they want is the “One weird trick your doctor is hiding from you” style content on the discover page, then I got nothing.