Quicksy

Jabber/XMPP with Easy Entry and Easy Discovery

Conversations

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

monocles chat

is a full-featured XMPP chat client

Element X - Secure Chat & Call

Sovereign. Seamless. On Matrix

Jami

Share, freely and privately

Threema Libre

Secure and private messaging

Session F-Droid

Encrypted private messenger

baresip+

VoIP User Agent app for Android based on baresip SIP library

baresip

VoIP User Agent app for Android based on baresip SIP library

Nextcloud Talk

Have private video calls and chat using your own server.

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

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