HubSpot CRM - Free CRM software for small businesses.
Onesheet CRM - The Simple CRM for Google Sheets
Bigin by Zoho CRM - Pipeline-centric CRM built and priced for small businesses
Freshsales CRM - A full-fledged CRM for high-velocity sales teams.
InStream CRM - Business relationship management platform - CRM alternative
erxes Mobile - Some of the most important CRM and web chat tools on the go