Really Good UX - A library of screenshots for UX inspiration
Open Loyalty for Startups - Open source stack for building customer focused products
Usability.gov - Resource for user experience (UX) best practices & guides
Promoter - The Most Effective Way To Engage And Learn From Customers
UX Check - Easy heuristic evaluations on your website (chrome ext.)
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.