Viable Fit - Measure and improve your product market fit
Crunchbase - Crunchbase is a platform for discovering industry trends, investments, and news about companies around the world.
Product Fit - Measure product/market fit in app with your users.
CB Insights - CB Insights is a company database for the venture capital and corporate development community.
Product/Market Fit Survey - Check how close your product is to Product/Market fit
Tracxn - data on companies