What app you americans use for personal conversations?
Here in South Europe people mostly use Viber.
Edit: I was very unaware about situation in Southern Europe as I've learned from this post...
Most people in Croatia use Viber!
I do cybersecurity and programming, so, stereotypically, Discord. It's more widespread than Matrix, and it's natively and easily cross-platform unlike iMessage, SMS, Telegram, or Signal.
I'd love to love Discord, but frankly it's one of the most convoluted, obtuse interfaces I've ever seen. And I wrote my first program in Fortran on punched cards...
True. It feels fine to me because I pretty much grew up on it, but introducing people to it is always rough (one friend group is still on Facebook Messenger).