Session messenger android client currently feels unpolished while simplex seems to require it to run in the background for instant notifications. Is there an alternative that is better than those 2?
It depends on many things, such as a threat modeling, opsec, etc. In terms of privacy and security !simplex@lemmy.ml seems to be superior.
Several reasons to that:
SimpleX doesn't have IDs, unlike Session. Which makes it more anonymous and private;
Ofc things like E2E encryption, forward secrecy and others;
Message mixing is and underrated feature, as well as content padding;
It has amazing security features such as self-destruct passwords, and a couple of others;
Can be self-hosted;
No need for phone number;
Leverage several 'accounts';
I have read their white paper, and is worth the time. Also, one of the episodes of the Opt Out podcast is with the SimpleX creator. I suggest listening. I personally liked the way he conceptualizes decentralization, and problematozes protocols.
I found SimpleX to be the best of all private messengers. Better than Session, Signal, XMPP, DeltaChat, and others. It is also more convenient than Briar and Threema.