Internet Down? No Cell Service? Use Your Phone To Communicate Offline

With the majority of people carrying cell phones today local cellular service can be disrupted when the normal daily traffic is surpassed. 
Anytime a large numbers people gather for a protest or any other reason local cellular service may become overloaded
disrupting cellular service.

First Responders
If You're a first responder make sure the telephone numbers of your agency and your personal cell phone have been registered with one of the three major priority Services to support National Security/Emergency Preparedness (NS/EP) activities: Telecommunications Service Priority (TSP), Government Emergency Telecommunications Service (GETS), Wireless Priority Service (WPS). They should be an important aspect of any emergency communications strategy, especially for those who rely on communications to respond to events and incidents on a daily basis and want to minimize their connectivity downtime.

But you can still communicate at least over short range using Bluetooth, Wifi, or a mesh network using these apps...

Offline Communication Apps 

The Serval Mesh

The Serval Mesh App aims at creating direct connections between cellular phones. The connections are made through their WiFi networks. There is no need for a mobile phone operator while forming the mesh with WiFi. The several Mesh app uses a store and forward system called Rhizome. Rhizome can achieve broad distance communication with minimal mesh connections.

Serval Mesh is open-source software. This allows you to make private phone calls, send secure messages and data. An ideal app to use in remote areas or during a disaster

Offline Messaging Mode: Peer to peer WiFi Direct with MDP encrypted | Download from PlayStore:  Serval Mesh

Bridgefy https://bridgefy.me Free to Business Pricing

The Bluetooth-based messaging app allows users (within a city) to communicate sans the internet. It has three operational modes

a) Person-to-person lets you chat privately with another user located within 100 meters or 330 feet of you

b) Mesh network, which lets you connect with users located further by communicating with Bridgefy users in the middle, thereby forming a human chain

c) Broadcast mode, which allows you to send out messages to every Bridgefy user around you at the same time, even if they are not in your contact list

FireChat creates a mesh network, and can transmit messages and pictures between devices located within 200 feet of one another. You can connect with another FireChat user via either public or private chat. Private messages are encrypted and can only be seen and read by the sender and the recipient. 

You can also create live chat rooms for discussions on any topic or relaying real-time information. FireChats multihop and store-and-forward technology helps it create larger networks when several users get on the app at the same time. 

Manyverse is a decentralized social networking app, which stores your data locally on your device as opposed to on a cloud.  The beta version of Manyverse hit Google Play Store last year, and has been installed over 5,000 times. 

The app requires no log-in, it doesn’t track your activity, and can be used to communicate with local users over peer-to-peer WiFi networks or Bluetooth.  It is a full-fledged social network containing user profiles, posts, comments, conversation threads, photos, videos, and ‘likeable’ and ‘shareable’ content. Unlike other social apps, however, Manyverse provides a clean, ad-free experience.

Briar is touted as one of the most secure messaging apps on Android. It functions both online and offline, and doesn't rely on a central server to store and sync messages.

When you’re out of internet, Briar lets you send messages via Bluetooth or local WiFi networks. When you get the internet back, the app syncs through the Tor network, thus letting users escape surveillance and tracking.

Signal Offline is one of the top messenger apps that lets you communicate over WiFi Direct. It functions without the internet and even cellular network.

The app tracks devices within a range of 100 meters, and displays them on your messaging list. You can send text, photos, audio, video messages – all of which are encrypted. 

Txti is a nifty tool to create quick, data-light web pages – which can open on slow networks and sometimes even without the internet.  It is particularly useful in times of crisis or during disaster management operations, where users can collate and share information easily from one central source. 

Txti creates a custom URL, which can be shared over Twitter or other networks for information dissemination. Each ‘txti’ can contain links, images, lists, headings, and more. Users can access Txti links on feature phones too. The only drawback is, the one creating the 'txti' needs to have access to the internet.