Lets Chat - Open source self-hosted chat app for small teams
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
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.
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
Telegram API - We offer two kinds of APIs for developers. The Bot API allows you to easily create programs that use Telegram messages for…
Plivo - Plivo simplifies your customer engagement.