Add Simple "Redeem" Button To Site Pages, Wordpress

We are using wordpress with a responsive theme. We only need a simple coupon redeem button added to the pages. See image for example. The button can only be pressed once per logged in user. Once it is pressed, it shows that the coupon has been redeemed - and it cannot be used again by the same user. Need to be able to control which pages this appears on in wordpress admin with a checkbox.