ChatSecure is a messaging application for iOS which allows OTR and OMEMO encryption for the XMPP protocol. Developed by Chris Ballinger and The Guardian Project
License: Open Source
Xabber is an open-source XMPP client that emphasizes flexibility and customization, whereas ChatSecure prioritizes privacy and security with features like Tor integration and default end-to-end encryption. Users looking for a customizable chat experience may prefer Xabber, while those focused on secure communications might opt for ChatSecure.