Conversations is an instant messaging app for Android based on the open XMPP (Jabber) protocol. It supports one-to-one and group chats, sharing of images and files, read markers that can be switched off, message history loaded from the server, synchronisation across devices, and end-to-end encrypted audio and video calls. For message encryption it supports OMEMO, which the project says provides forward secrecy and plausible deniability, as well as OpenPGP. It requires Android 6.0 or later. Because XMPP is a federated protocol, users choose their own server or provider.
Conversations is free software under the GPLv3, with its source code on Codeberg. It is developed by volunteers, led by Daniel Gultsch, and can be bought on Google Play, installed from F-Droid or built from source. The app does not host messages itself: they are stored on the XMPP server the user chooses, which can be run by a provider in the EU or by the organisation itself. For a European organisation this allows control over where data is hosted and, through OMEMO, over who can read message content.