Marketing 360 - Marketing 360® is a powerful marketing and website platform built for any size brand. It's fully managed and has everything a brand needs to drive beautiful marketing and sales.
Twilio - Brings voice and messaging to your web and mobile applications.
SendX.io - SendX (https://sendx.io) provides remarketing and retargeting tools for web businesses. You can use popups, landing pages, email, web push notification, automation workflows and FB / Google retargeting to drive more revenue.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
HubSpot - Grow Better With HubSpot: Software that's powerful, not overpowering. Seamlessly connect your data, teams, and customers on one CRM platform that grows with your business.
BulkSMS - SMS messaging service provider offering two-way SMS communication services.