OpenCart - A free shopping cart system. OpenCart is an open source PHP-based online e-commerce solution.s
Asklayer.io - Get real answers from your customers with Asklayers surveys, quizzes, polls and more. Works on any website with zero code and includes enterprise level features such auto-segmentation, user tagging, branching, NPS & CSAT calculation.
PayKickstart - PayKickstart is the ultimate shopping cart and affiliate management platform, empowering online Entrepreneurs and digital publishers with the tools to sell their products online.
Ask User - User surveys without stress
Gumroad - An all-in-one solution to sell your work and grow your audience.
Doorbell.io - Collect in-app user feedback. Available on websites, iOS, and Android.