Nostr-double-ratchet ts & rust libraries and ndr command line tool: https://files.iris.to/#/npub1xndmdgymsf4a34rzr7346vp8qcptxf75pjqweh8naa8rklgxpfqqmfjtce/nostr-double-ratchet
Chat.iris.to code: https://files.iris.to/#/npub1xndmdgymsf4a34rzr7346vp8qcptxf75pjqweh8naa8rklgxpfqqmfjtce/iris-chat
No other client using it atm
