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
ChatSecure is primarily focused on secure messaging and supports multiple protocols, while Sicher emphasizes end-to-end encryption and includes features for voice and video calls. Both prioritize user privacy, but their use cases differ, with ChatSecure being more versatile for various messaging protocols.