Twilio - Brings voice and messaging to your web and mobile applications.
BroadSoft UC-One - UC-One is a suite of cloud communications offering business phone services, messaging, audio and video conferencing, and more.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
NextCall - 1 click to join upcoming Zoom calls (and other video calls)
BulkSMS - SMS messaging service provider offering two-way SMS communication services.
CamCard - CamCard reads business cards and save instantly to phone Contacts.