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.
you don’t need a camera, you can load the qrCode image (after sending it through Signal 🤭