Applozic - Chat API & In-App Messaging SDK for Mobile & Web Apps Innovate fast, save development cost and delight users with a scalable, secure and customizable Chat

Qiscus - Engage your customers from your own apps and mainstream chat apps like Whatsapp, LINE, Facebook Messenger, Telegram, Email, Twitter, Instagram, etc. and centralize all chats into a single dashboard.

Chat by Stream - Build and ship in app messaging in a few hours

WeChat API - WeChat API and SDK allow developers to access and integrate the functionality of WeChat with other applications.

MirrorFly - World's Most Scalable Voice, Video & Chat SDK for Small, Medium & Enterprises

Lets Chat - Open source self-hosted chat app for small teams