For those who, like myself, have never heard of Session prior to now:

https://en.wikipedia.org/wiki/Session_(software)

Session is an Australian, currently Switzerland-based, cross-platform end-to-end encrypted instant messaging application emphasizing user confidentiality and anonymity. Developed and maintained by the non-profit The Session Technology Foundation,[3] it employs a blockchain-based decentralized network for transmission. Users can send one-to-one and group messages, including various media types such as files, voice notes, images, and videos.[4]

Session provides applications for various platforms, such as macOS, Windows, and Linux, along with mobile clients available on both iOS and Android.