Rather than a direct "idea marketplace," you should target these entities based on your development stage:
Y Combinator : Known for their "Requests for Startups," they actively seek ideas in specific categories like AI-native services, healthcare administration, and climate tech. companies that buy app ideas
: Large companies in specific industries (e.g., fintech, healthcare, logistics) often acquire smaller startups or prototypes that fill a gap in their existing product line. Rather than a direct "idea marketplace," you should