yaxim is an open-source XMPP client designed for Android users who want to have unlimited messaging on their data plan. The app offers security, low overhead, and keeps your server connection open. It only supports a single account, but it has many features such as immediate reconnection on 3G/WiFi network changes (seamless with XEP-0198), allowing automatic connection after turning on your phone, roster management support, and persistent message history. Additionally, yaxim supports Message Carbons (XEP-0280), and you are asked about self-signed SSL certificates.

yaxim is optimized to use the yax.im free XMPP service, which makes it an excellent choice for those who are looking for a free XMPP client that is reliable, secure, and easy to use. If you are an Android user and want to have unlimited messaging on your data plan, yaxim is the perfect solution for you.