Conversations

Encrypted, easy-to-use XMPP instant messenger for your mobile deviceGPL-3.0-only

Quicksy

Jabber/XMPP with Easy Entry and Easy DiscoveryGPL-3.0-only

blabber.im

is an Open Source XMPP/Jabber Messenger for AndroidGPL-3.0-only

StoneAge

A self-hosted P2P messenger - you will need an S3 bucket to use itGPL-3.0-only

monocles chat

is a secure XMPP chat client for AndroidGPL-3.0-only

Snikket

GPL-3.0-only

Deku SMS

Deku is an SMS app that supports end to end encryption and photo sharingGPL-3.0-or-later

Wire • Secure Messenger

Wire offers highly secure communication – anywhere and anytime.GPL-3.0-or-later

Cheogram

Chat on the Jabber network (XMPP protocol); focus on features for gateway usersGPL-3.0-only

Text Torch

Shine a light on your texting behaviorGPL-3.0-or-later

Goguma

An IRC client for mobile devicesAGPL-3.0-only

kboard

Keyboard with customisable one-click responses and powerful automation commands.GPL-3.0-only

QQ Notification Evolution

Optimize QQ notification without ROOTAGPL-3.0-only

Limpazap

Clean old WhatsApp backupsMIT

Silence

Encrypted SMS/MMS conversations made easy!GPL-3.0-only

MusicBrainz

The Official MusicBrainz AppGPL-3.0-or-later

QKSMS

Messaging appGPL-3.0-only

Element X - Secure messenger

Fastest ever Matrix clientApache-2.0

Cryptomator

Put a lock on your cloud: Take the security of your data into your own handsGPL-3.0-only

Friend Alert

Nurture distant friendships with timely remindersAGPL-3.0-only