Twilio - Brings voice and messaging to your web and mobile applications.
AirDroid - Access Android phone/tablet from computer remotely and securely. Manage SMS, files, photos and videos, WhatsApp, Line, WeChat and more on computer.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Pushbullet - Pushbullet - Your devices working better together
Plivo - Plivo simplifies your customer engagement.
MyPhoneExplorer - WHAT IS MY PHONE EXPLORER? Imagine if your PC could be used to keep track of your mobile phone? How would you utilize a PC client that connects to your phone? Read more about MyPhoneExplorer.