Quicall

Secure messaging with chat, voice and video calls.

Olvid

為所有人提供的私密訊息

baresip+

VoIP and mobile calling and messaging app based on baresip library

baresip

VoIP and mobile calling and messaging app based on baresip library

Duetto

A tiny Discord for two, on your own server: a permanent voice and video channel.

Conversations

可加密、易於使用的 XMPP 即時訊息，為您的行動裝置設計

Wire • Secure Messenger

Wire offers highly secure communication – anywhere and anytime.

TRIfA

TRIfA Tox Client

Session F-Droid

Encrypted private messenger

Ermis

Ermis M is an open-source, privacy focused mobile chat application.

SimpleX Chat

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

Nextcloud Talk

Have private video calls and chat using your own server.

another.im

Yet Another Conversations fork but...

Threema Libre

Secure and private messaging

aTalk

XMPP/Jabber client with encrypted instant messaging and video calls

Element X - Secure Chat & Call

Sovereign. Seamless. On Matrix

Jami

自由且私密地分享

Element Classic

Previous generation Element

Cheogram

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

monocles chat

is a full-featured XMPP chat client

Jitsi Meet

Instant video conferences efficiently adapting to your scale

Mumla

Voice chat on Mumble servers

Snikket

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

Linphone - open source SIP client

SIP（VoIP）電話

Meshenger

一個開源的端對端

ThreatScoopOnionChat

A Forked Version focused on privacy from SESSION

Sipdroid

SIP（VoIP）用戶端

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.