UI Movement - The best UI design inspiration, daily
RetailMenot - The RetailMeNot mobile app allows you to find deals on the go for both online shopping and in store shopping.
Design Hunt - Curated design inspiration for everyone
Slickdeals.net - Slickdeals: The Best Deals, Coupons & Discounts on everything
Page Flows - User flow design inspiration for mobile & desktop
Honey - Honey is a browser extension that automatically finds and applies coupon codes at checkout with a single click.