NetHunt CRM - Turn Gmail into a smart CRM
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.
Immediately - Mobile sales email and CRM management for Gmail & Salesforce
Streak - Manage customers inside Gmail
Pagevamp - Turn your Facebook page into a website.
Pigeon for Gmail - A powerful CRM and automation suite built inside Gmail.