Relay

Relay is a fast, private, and offline messaging app that lets you communicate with nearby devices using Bluetooth. No internet, Wi-Fi, or mobile data is required.
Key features:
Offline messaging without internet
Bluetooth-based device discovery and connection
Simple and modern dark-themed interface
Quick pairing with nearby devices
Local communication without cloud storage
No online tracking of your messages or location
Stay connected with nearby people, even when you're completely offline.