Carrd - Simple, responsive one-page site creator.
Viable Fit - Measure and improve your product market fit
Cargo - Cargo Collective is a web publishing platform that creates and offers accessible tools online.
Product Fit - Measure product/market fit in app with your users.
Responsivize - A must-have tool to develop responsive websites
Product/Market Fit Survey - Check how close your product is to Product/Market fit