hmm no one said matrix. i rather like matrix. the whole key and passcode seems to confuse people but once its set up its nice and free... and you can host your own server if youre super paranoid.
Haven't tried Session, though it seemed like a good service, until I found it lacks perfect forward secrecy, which IMO seems like a bad decision. I think Berty seems interesting too, but it seems like it might take a short while before it becomes a relevant option.
Also not a fan of Session missing FS. So I replaced it with SimpleX, but it's quite a dead community. The app also feels like something beta, but I have high hopes for it