RetailMenot - The RetailMeNot mobile app allows you to find deals on the go for both online shopping and in store shopping.

Groupon - Each day Groupon offers a deal through local vendors in your city.

Dealspotr - Dealspotr is like Wikipedia for deals.

Honey - Honey is a browser extension that automatically finds and applies coupon codes at checkout with a single click.

Pedlar - Rather than selling the products of the online retailers and offering the discount and daily deals by these online retailers, Pedlar basically work as an online platform where willing sellers and potential customers meet to make the deals.

Slickdeals.net - Slickdeals: The Best Deals, Coupons & Discounts on everything