TapTalk.io - TapTalk.io is a complete in-app chat SDK and messaging API - Easy integration and customizeable.
Parse - Build applications faster with object and file storage, user authentication, push notifications, dashboard and more out of the box.
Chat by Stream - Build and ship in app messaging in a few hours
AWS Amplify - JavaScript library for app development using cloud services
MirrorFly - World's Most Scalable Voice, Video & Chat SDK for Small, Medium & Enterprises
AWS Mobile Services - Storage, Analytics, Push Notif. & SMS Delivery SDKs