InStream CRM - Business relationship management platform - CRM alternative
Zendesk Sunshine - Open, flexible CRM platform built on AWS
Crmble - Easy peasy crm for Trello
Wobaka - Refreshingly Simple CRM And Email Automation
Followup.cc - FollowUp for email is a lightweight productivity suite that keeps your conversations and tasks from slipping through the cracks. Set perfectly timed reminders that arrive at the top of your inbox, right when you need them.
Onesheet CRM - The Simple CRM for Google Sheets