OurCity is a city building game that is used to promote civic engagement within Jordan. This is a great cause supported by USAID. I’ve built a coupon redemption site, similar to many redemption sites where you enter unique codes and receive a prize of sorts.
As an aside, administrators and event leaders could create any event they would like. The admin portal created lists of codes which could then be printed and handed out at the events. When users came online, they selected the event they were at and could input their code.