NetHunt CRM - Turn Gmail into a smart CRM
Affinity - Relationship Intelligence, Reimagined
Immediately - Mobile sales email and CRM management for Gmail & Salesforce
Folk - The next generation contact manager
Streak - Manage customers inside Gmail
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.