Service - Customer service issues solved for you, on demand, for free.
InsightSquared - #1 for Salesforce.com Pipeline forecasting, profitability analysis, activity tracking: all the small business intelligence you need. Works using CRM data and automatic syncing.
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
Aviso - Aviso provides predictive analytics software to help sales organizations optimize their performance and exceed revenue goals using machine learning algorithms and portfolio management techniques.
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.
Sidekick by Hubspot - Customer insight integrated with your email tools.