Apps similar to ChatSecure include Signal, which is free and open source. Other options are Telegram, Element, Tox and SimpleX Chat. Instant Messengers like ChatSecure are a crowded field, with more than 100 alternatives for Android, iPhone, Windows, Linux and Mac.
Bitmessage is a P2P communications protocol used to send encrypted messages to another person or to many subscribers. It is decentralized and trustless, meaning that you need-not inherently trust any entities like root certificate authorities.
The most secure and anonymous messenger, encrypted with Blockchain.
Estonia
EU
Android keyboard for secure E2EE communication through the signal protocol in any messenger. Communicate securely and independent, regardless of the legal situation or whether messengers use E2EE.
Switzerland
Kaidan is a simple, user-friendly Jabber/XMPP client providing a modern user interface using Kirigami and QtQuick. The back-end of Kaidan is written in C++ using the QXmpp XMPP client library and Qt 5.
GermanyEU
Quaternion is a cross-platform Qt5-based desktop IM client for Matrix, a reference desktop application using libQMatrixClient. Source code, issue tracker, roadmap etc. can be found at GitHub. Releases (with links to cross-platform source code archives, as well as binaries for...
TeleGuard is the data-secure messenger from Swisscows. TeleGuard encrypts every message and all telephone calls with encryption algorithm currently available: SALSA 20. TeleGuard servers are located in Switzerland, they are not subject to the data protection laws of the EU /...
Switzerland
Protect your communication in transit and on your phone. Silence (formerly SMSSecure) is a full replacement for the default text messaging application: all messages are encrypted locally and messages to other Silence users are encrypted over the air.
Quantum-resistant encrypted messaging, video/audio calls, and file transfers in the browser with optional registration and no downloads required.
United States
Open source Jabber (XMPP) client with multi-account support, clean and simple interface. Being both free (as in freedom!) and ad-free, Xabber is designed to be the best Jabber client for Android .
United States
Sphinx.chat lets you use your lightning node to talk to anyone else who is running lightning and a sphinx compatible chat client.
An encrypted instant messaging with video call and GPS features for android.
