Bridgefy is an app that enables users to chat with friends nearby via Bluetooth when they do not have phone service and Internet connection. Read more about Bridgefy  

There are times when our mobile device has no signal, and we cannot even send an SMS or connect to the Internet. Bridgefy aims to be the perfect solution for these situations, whether you are in a remote village, inside a crowded stadium, or in a foreign country.
The messaging app works offline and helps you communicate with nearby friends, colleagues, or family once you turn on the Bluetooth functionality. They must also have Bridgefy accounts and be within 100 meters (330 feet) of you.
Furthermore, you can talk with people at a maximum distance of 200 meters (660 feet) as long as other users are in the middle. It is worth mentioning that all your conversations remain private and that those persons centrally located cannot read your chats.
Another significant feature of this mobile solution is the Broadcast room. In this section, you may communicate with all Bridgefy users in your proximity, even if they are not on your contacts list.
Besides all these benefits, users can enjoy the online mode and turn on their Internet connection to chat with friends across the world.