This article describes how to install an XMPP client on Android and create an account in XMPP federation. A free open source application "Conversations Legacy" is used as a client, and 404.city as a server. Through the Conversations client, you can exchange files by transferring via a link, even for those who do not have XMPP installed. Conversations has several types of encryption (OTR, PGP, OMEMO), support for the TOR network and is approved as a secure messenger by the Prisma Break project. The client has support for encrypted, private, group chats and XMPP public conferences. The 404.city server officially supports full compatibility with the Conversations client, has a set of modern XMPP extensions and an increased level of privacy protection
Steps
Part 1 of 2: Registering with the XMPP Server

Step 1. Enter “Conversations Legacy” in the Play Store search
Note that there are two XMPP clients, Conversations and Conversations Legacy. These are different versions of the application from the same developer. Conversations is a paid version, Conversations Legacy is free. Don't confuse them, you don't necessarily have to spend money on purchasing the paid version. This article describes how to install the free version of "Conversations Legacy"
2 Click Install 3 After installing the application, click on the "Conversations" icon and open the application The default "Conversations.im" server becomes paid after 6 months of maintenance.
5 Registering to the XMPP Server. Server 404.city officially provides free server compatibility support with Conversations. If the XMPP server does not have the necessary support for XMPP extensions, the Conversations client may work with errors: not transferring files offline, using up your smartphone battery more, encryption may not work in the client, synchronization across multiple devices, and so on. 6 Enter captcha If the form for uploading an avatar appears, it means that the Jabber account has been successfully created! Registration completed
8 In the account settings, by clicking on the button with three dots, you can see the list of available server extensions (XEP) 1 Add the contact of the interlocutor. XMPP addresses are similar to email addresses. Users from different servers can talk to each other, unless prohibited by the server's policy. To communicate between different servers, you must wait until the interlocutor authorizes your contact. An XMPP user can join conferences on other servers. A conference is added to Conversations, just like a contact, but in the next tab "conferences"
2 To see the presence or absence of the interlocutor within the conversation, go to the settings and select the "Use indicator button" 3 After that, the send button will change color depending on the availability of the interlocutor
Step 4. After the application has opened, click on the inscription "Use your provider"
Step 7. Add an avatar
Part 2 of 2: Using and Configuring Conversations