Evercontact - Your contacts always up to date and automatically with Evercontact.
Cloze - Smarter Relationship Management
CONTACTBOX - CONTACTBOX combines the simplicity of an address book with effective functions of a CRM system.
Propeller CRM - Small business CRM with deep Gmail integration
Bigin by Zoho CRM - Pipeline-centric CRM built and priced for small businesses
Streak - Manage customers inside Gmail