Sphinx Chat is described as 'Sphinx.chat lets you use your lightning node to talk to anyone else who is running lightning and a sphinx compatible chat client' and is a Group Chat app in the social & communications category. There are more than 50 alternatives to Sphinx Chat for a variety of platforms, including Android, iPhone, Mac, Windows and Linux apps. The best Sphinx Chat alternative is Signal, which is both free and Open Source. Other great apps like Sphinx Chat are Telegram, Element, Matrix and Tox.
Zulip is the only modern team chat app that is designed for both live and asynchronous conversations. Zulip topics create a separate space for each discussion, so different conversations will never get in each other's way.
RetroShare is a open source cross-platform, private and secure decentralized communication system. It lets you to securely chat, share photos, videos, and more, using OpenPGP to authenticate peers and .
FluffyChat is an open, nonprofit and cute matrix messenger app for Ubuntu Touch, Android and iOS.
Keybase is a new and free security app for mobile phones and computers. For the geeks among us: it's open source and powered by public-key cryptography.
Delta Chat looks and feels like other popular messenger apps, but does not involve centralized control, tracking or selling you, friends, colleagues or family out to large organizations. "Privacy by Design" has never been more fun.
Conversations is a privacy focused, open source XMPP Texting [Jabber] client for Android 4.0+ smart phones with wife-approved easy encryption [OTR, OMEMO, or GPG].
Linphone is one of the most famous open source softphones in the world. It is fully SIP-based, for all calling, presence and IM features.
Trillian is an instant messaging app that works on phones, tablets, and desktops while keeping your chats neatly synchronized between all of them! We think conversation should be easily shared between all of your devices, not trapped as text messages on your phone.
Messages is Google's communications app for Android to helps send and receive SMS and MMS messages. You can also send group texts as well as your favorite pictures, videos and even audio messages to your contacts.
An alternative Telegram client based on TDLib, with higher speed, slicker animations and experimental features.
Berty is a secure peer-to-peer messaging app that works with or without internet access, cellular data or trust in the network. Berty is a privacy-first messaging application built on top of the Berty Protocol.
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