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

Evercontact - Your contacts always up to date and automatically with Evercontact.

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

CONTACTBOX - CONTACTBOX combines the simplicity of an address book with effective functions of a CRM system.

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

Bigin by Zoho CRM - Pipeline-centric CRM built and priced for small businesses