Psi is a cross-platform powerful XMPP/Jabber client (Qt, C++) designed for the Jabber power users. Psi+ is a development branch of Psi IM XMPP/Jabber client. Developed by http://psi-plus.com/
License: Open Source
Psi+ offers a more comprehensive set of features including file sharing and voice/video calls, making it suitable for both personal and professional use. In contrast, ChatSecure prioritizes security and simplicity, making it ideal for users who value anonymity and robust encryption.