Sharetribe - Build your online marketplace business. You don't need a developer.
UI Movement - The best UI design inspiration, daily
Arcadier - Build an online marketplace in minutes, no coding required.
UI Garage - Specific mobile and web design patterns for your inspiration
Shopify - Shopify is a powerful ecommerce platform that includes everything you need to create an online store and sell online. Try it free for 14 days.
UI8 - Carefully crafted UI design assets