Findnlink - Find people to work with on your ideas.
SaaSmate.co - Find product partnerships that drive growth
CollabFinder - Find cofounders and makers to help build your project
Productroad - Build better products based on customers feedback
Co-founder Question Cards - Questions to ask your co-founder to know each other better.
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.