Quicksy

Jabber/XMPP with Easy Entry and Easy Discovery

Conversations

Encrypted, easy-to-use XMPP instant messenger for your mobile device

Jami

Share, freely and privately

baresip+

VoIP User Agent app for Android based on baresip SIP library

baresip

VoIP User Agent app for Android based on baresip SIP library

Session F-Droid

Encrypted private messenger

monocles chat

is a full-featured XMPP chat client

Nextcloud Talk

Have private video calls and chat using your own server.

Element X - Secure Chat & Call

Sovereign. Seamless. On Matrix

Element Classic

Previous generation Element

TRIfA

TRIfA Tox Client

SimpleX Chat

SimpleX Chat - e2e encrypted messenger without any user IDs - private by design!

Snikket

Personal messaging app for groups, with a self-hostable open-source server

Mumla

Voice chat on Mumble servers

Wire • Secure Messenger

Wire offers highly secure communication – anywhere and anytime.

aTalk

XMPP/Jabber client with encrypted instant messaging and video calls

Cheogram

Chat on the Jabber network (XMPP protocol); focus on features for gateway users

Linphone - open source SIP client

SIP (VOIP) phone

Threema Libre

Secure and private messaging

Jitsi Meet

Instant video conferences efficiently adapting to your scale

Meshenger

Voice- and video phone App for off-the-grid scenarios.

ThreatScoopOnionChat

A Forked Version focused on privacy from SESSION

another.im

Yet Another Conversations fork but...

aTox

aTox, a beautiful and modern Tox client

Sipdroid

A SIP (VOIP) client

Databag

A federated chat client designed for privacy and selfhosting.

StoneAge

A self-hosted P2P messenger - you will need an S3 bucket to use it

unofficial Stud.IP-app

An unofficial app for Stud.IP systems.

Lumicall

SIP softphone