Twilio - Brings voice and messaging to your web and mobile applications.
Sheety - Turn any Google sheet into an API instantly, for free. Power websites, apps, or whatever you like, all from a spreadsheet. Changes to your spreadsheet update your API in realtime. Neat
Plivo - Plivo simplifies your customer engagement.
Sheetsu - Turn Google Spreadsheet into API
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
SheetBest - Turn a Google SpreadSheet into a JSON Database API