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.
Twilio - Brings voice and messaging to your web and mobile applications.
MailChimp - MailChimp is the best way to design, send, and share email newsletters.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Marketo - Marketo's powerful marketing automation software helps marketers master the art & science of digital marketing to engage customers and prospects.
BulkSMS - SMS messaging service provider offering two-way SMS communication services.