https://getsession.org/
Session | Send Messages, Not Metadata. | Private Messenger
Session is a private messenger that aims to remove any chance of metadata collection by routing all messages through an onion routing network.
metadata private messenger
https://getsession.org/litepaper
Session Litepaper: Send Messages, Not Metadata - Session Private Messenger
Session is a decentralised messenger that supports completely private, secure, and anonymous communications.
metadata private messenger