Signal for those who have it and SMS for everyone else

Signal, mostly because I value my privacy though.

1. Signal
2. SimpleX

Signal. It's in the perfect middle ground of security and usability. Security enthusiasts will tell you it isn't good enough. It's fine, and it's certainly better than Facebook Messenger.

I've wrangled over this very question for years. I've looked at all the research, I've read all of the articles and I've witnessed all of the armchair security 'experts' make their claims one way or the other. I got so exhausted bouncing back and forth between a dozen screamed opinions, I walked away. In the end, I decided to go with Signal and it has served my needs for a secure and private instant messenger with no ads or shady crypto-scams without fail.

I feel like Delta Chat should be mentioned here as a secure, decentralized and pretty awesome alternative.

It also allows to communicate with non-delta chat users via email through the same chat interface

WhatsApp like app is Signal. Other ones are better in terms of privacy but you have to convince contacts to use that, so….

Snikket.org Open Source, real End-to-end encryption (OMEMO), and you can use other clients if you don't like theirs. You can also self-host.

I was just about to ask this, so thanks, OP, and thanks, answer-givers.