Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Siberian CMS - Siberian is an Open-Source and Free App Maker. Unlimited Push Notifications. Unlimited features. Fully Customizable. Download it and build your own app now!
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
Dropsource - Mobile development platform for building native iOS & Android apps
Plivo - Plivo simplifies your customer engagement.
GoodBarber - GoodBarber is a mobile app creation platform.