Five9 - Five9 provides cloud-based call center software for sales, marketing and support.

Zendesk - Zendesk is a beautiful, lightweight help-desk solution.

RingCentral - RingCentral is the leading provider of cloud-based communications and collaboration solutions for small business and enterprise companies

Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community

Aircall - Aircall is a call center software of a new generation designed for fast growing companies. Setup instantly and integrates to your CRMs

HelpScout - Help Scout is a simple, straightforward way to provide excellent support