baresip+

SIP and mobile calling and messaging User Agent for Android based on baresip lib

baresip

SIP and mobile calling and messaging User Agent for Android based on baresip lib

TRIfA

TRIfA Tox Client

Jami

自由且私密地分享

Element X - Secure Chat & Call

Sovereign. Seamless. On Matrix

Wire • Secure Messenger

Wire offers highly secure communication – anywhere and anytime.

Threema Libre

Secure and private messaging

Quicall

Secure messaging with chat, voice and video calls.

aTalk

XMPP/Jabber client with encrypted instant messaging and video calls

SimpleX Chat

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

Element Classic

Previous generation Element

Cheogram

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

Session F-Droid

Encrypted private messenger

Nextcloud Talk

Have private video calls and chat using your own server.

Olvid

為所有人提供的私密訊息

Conversations

可加密、易於使用的 XMPP 即時訊息，為您的行動裝置設計

another.im

Yet Another Conversations fork but...

monocles chat

is a full-featured XMPP chat client

Ermis

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

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.