Zendesk - Zendesk is a beautiful, lightweight help-desk solution.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
ServiceNow - ServiceNow automates and manages global enterprise service relationships. Create a single system of record for enterprise services, automate manual tasks, consolidate legacy ITIL systems.
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
InvGate Service Desk - InvGate Service Desk is a web-based ITIL-ready solution with an unprecedented user interface.
Plivo - Plivo simplifies your customer engagement.