Signal ?

Signal, hello?

Signal.

Signal!

nothing better than Signal

Signal is probably the simplest to get started with.

There is also element/matrix for more of a discord type feel.

SimpleX if you want something more anonymous.

Everyone is saying Signal, but my family uses a Matrix space (mix of phones and PCs in this case) and it works great. It's FOSS, federated. Truly future-proof.

https://www.privacyguides.org/en/real-time-communication/

signal, simplex

I'd recommend Threema. It's privacy focused, based in Switzerland. You don't even need a phone number to create an account, they collect no data on you (claimed, but haven't checked) and the code is open source, under A-GPL 3 license.

There's a build for Apple and Android, for which you pay once.

I use this to talk with important family members.

Signal

Signal is a nice suggestion but is based in the US meaning they could be subpoenaed and legally not allowed to say. It's unlikely you'd be targeted though, unless you're a very high-profile person. If you're concerned about where servers are being run and who by then matrix is a great alternative.

I've been using Delta Chat for the last few weeks, its very similar to WhatsApp, but decentralised... Works very well, available on android & ios, definitely worth a look, as it could be good for your use case..

https://delta.chat/en/

Matrix?

I just got to know about Delta Chat which sounds fantastic as it basically uses your email but wrapped as chat.

XMPP and Matrix are other good options too, although these require creating an account (Delta Chat can work with your normal email account).

The good thing about these last 2 is that they have calls and all that stuff.

I'll be different and say Session.

I run my own XMPP server. https://joinjabber.org/ has some introductory information Snickket is a all in one service you can host or your can pay them to host https://snikket.org/start/

XMPP servers and clients are a lot lighter weight than matrix, though I think matrix has more fancy features.

They're both self hostable and are federated to share the costs of running the network.

With signal there's a non-profit that needs some pretty steam funding to stay in business. (Though they're popular so maybe they can get it) https://www.pcmag.com/news/want-to-run-an-encrypted-chat-app-youll-need-50-million-signal-says