Onesheet CRM - The Simple CRM for Google Sheets
InStream CRM - Business relationship management platform - CRM alternative
HubSpot - Grow Better With HubSpot: Software that's powerful, not overpowering. Seamlessly connect your data, teams, and customers on one CRM platform that grows with your business.
GetStream.io - APIs for the development of scalable newsfeeds and chat applications.
Crmble - Easy peasy crm for Trello
Pipedrive - Sales pipeline software that gets you organized. Helps you focus on the right deals, so easy to use that salespeople just love it. Great for small teams.