SimpleX Chat is an instant messenger that is decentralized and doesn’t depend on any unique identifiers such as phone numbers or usernames. Users of SimpleX Chat can scan a QR code or click an invite link to participate in group conversations.
-privacyguides.org
It’s clearly proving to be the most innovative technology when it comes to decentralized communication, in my opinion.
There is a desktop app but linking is not as easy and featured as Session, which is really easy to use on multiple devices, but then you lose the superior security of SimpleX