Firechat.
How does FireChat work
without Internet?
FireChat is a messaging app
that lets iOS and Android smartphone users chat without a cellular or Internet
connection. ... When in the “Nearby” mode, the app uses Bluetooth to connect
nearby phones to form a wireless mesh network that enables chat messages to
pass from phone to phone without going through the Internet.
Bridgefy.
Bridgefy is an offline
messaging app that lets you communicate with friends and family when you don't
have access to Internet, by simply turning on your Bluetooth antenna. Ideal for
music festivals, sports stadiums, rural communities, natural disasters,
traveling abroad, and much more.
WhatsApp.
A new feature on WhatsApp’s
latest update allows users to send messages even when there is no network or
internet connection in the smartphone. In a similar feature that is present in
Facebook Messenger, emails and messages, WhatsApp in its latest iOS update
enables users to queue up messages even if they are offline.
The Serval Mesh.
Hike.
Signal Offline Messenger.
Briar.
GO SMS Pro.