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

Correlated - Correlated is the ML-powered tool that helps you convert your self-serve SaaS users and accounts into paid customers.

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

Prospect.io - Prospecting, like a boss. Find any email, reach out, measure everything and integrate with your CRM.

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

Calixa - Calixa gives product-led GTM teams the insights they need to find, close, and grow customers amidst a sea of self-serve signups.