Mesibo - Open Source Messenger app for iPhone and iPad

Mesibo Messenger is an open-source app with real-time messaging, voice and video call features.

Features
One-on-one messaging and Group chat
High-quality voice and video calling
High-quality voice and video conferencing
End-to-End Encryption
Rich messaging (text, picture, video, audio, other files)
Encryption
Location sharing
Message status and typing indicators
Online status (presence) and real-time profile update
Push notifications

The entire source code is available from the GitHub repository https://github.com/mesibo/messenger-app-ios