[Free Add-on ] Upgrade Coupons by Waindigo 1.0.9a

About
Add the ability for coupons to be created in the Admin Control Panel to be used when your members purchase account upgrades.

Email or post your coupon codes to members so they can use them as a discount when purchasing account upgrades, upto and including free upgrades.
Coupons currently only work for non-recurring upgrades. If using User Upgrades by Waindigo user upgrades with trial periods and tiered upgrades cannot have coupons applied to them.

For a contribution of any amount, you may install the add-on on a commercial site, and no additional add-ons are required to be installed. You can even use CSS or Javascript to hide the copyright notice.