UI Movement - The best UI design inspiration, daily
Square Online Store - Build your own online store with Square
UI Garage - Specific mobile and web design patterns for your inspiration
Swell.is - Customizable, API-first ecommerce platform for innovative brands, startups, and agencies.
UI8 - Carefully crafted UI design assets
WooCommerce - A freely available eCommerce plugin that enables shop facilities on your WordPress website. Functionality enabling extensions & beautiful themes available.