Twilio - Brings voice and messaging to your web and mobile applications.
Kissflow - Kissflow is a workflow tool & business process workflow management software to automate your workflow process. Rated #1 cloud workflow software in Google Apps Marketplace.
RingCentral - RingCentral is the leading provider of cloud-based communications and collaboration solutions for small business and enterprise companies
Process Street - Create beautiful rich process documents in a simple to follow checklist format. Fast, free and incredibly simple to use.
CallHippo - Easy to use Phone System with World-Class Support
Pipefy - Pipefy is a process management software that empowers anyone to create and automate efficient workflows on their own without code.