What's a good iOS app for secure and private communication with disappearing messages?

Oh, definitely check out Signal. I’ve been using it for ages to chat with friends and even for some work stuff where privacy really matters. The disappearing messages feature is super handy—you can set a timer from 5 seconds up to a week, and poof, the message is gone for everyone. No screenshots warning, though, so keep that in mind! What’s cool is everything’s encrypted end-to-end, so even Signal can’t see your chats. I use it for sending login codes or just silly stuff I don’t want hanging around. Group chats support it too, which is nice when you’re planning a surprise and don’t want clues left behind. The app’s free, no ads, and honestly just feels lightweight and reliable. Only bummer—if someone doesn’t have Signal, you gotta convince them to download it, but once they do, it’s seamless.