Based on our record, Y Combinator Co-founder Matching seems to be more popular. It has been mentiond 1 time since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
One idea I just remembered is to find a business co-founder that already knows a market well and sees an opportunity. Startup School's co-founder matching service is quite good. Source: almost 3 years ago
PitchWall - Browse new startups, and submit your mobile app/games startup's beta page here.
CoFoundersLab - Meet 250,000+ entrepreneurs online
Growing Page - Browse web projects and evaluate them by multiple criteria.
Founders Nation - Find or become a startup cofounder
Product Hunt - A website that lets users share and discover new products
Find A Maker - find a partner for your next project