What are some alternatives?
When comparing QuickBlox and Mirrorfly, you can also consider the following products
Twilio - Brings voice and messaging to your web and mobile applications.
SendBird - SendBird is messaging-as-a-service.
Plivo - Plivo's Voice API enables businesses to build Voice apps to reach customers globally in 200+ countries. Try Plivo's Voice API for free. Instant Sign Up.
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
Contus Fly - Contus Fly, an instant messaging solution for real-time mobile chat app development. Build 100% customizable mobile chat . be reachable at any given time.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates