wordpress coupon code plugins

We need custom plugin for our wordpress that allow our user to post the coupon on our site. Once post, it will notify us and we will have to approve the coupons before it get posted into the sites. Coupon: Expired: Description: This is coupon is for our review site, therefore the coupons will appear on each of the review page that we have && We also able to add the coupon ourself as well If you need more information please do not hestitate to ask