Zendesk Sunshine - Open, flexible CRM platform built on AWS
HubSpot CRM - Free CRM software for small businesses.
Crmble - Easy peasy crm for Trello
Bigin by Zoho CRM - Pipeline-centric CRM built and priced for small businesses
InStream CRM - Business relationship management platform - CRM alternative
Wobaka - Refreshingly Simple CRM And Email Automation