Simple Poll - The easiest way to create polls in Slack
RetailMenot - The RetailMeNot mobile app allows you to find deals on the go for both online shopping and in store shopping.
GitHub Polls - Polls for GitHub issues and readme
Slickdeals.net - Slickdeals: The Best Deals, Coupons & Discounts on everything
minipoll - Create simple shareable polls in seconds
Honey - Honey is a browser extension that automatically finds and applies coupon codes at checkout with a single click.