This may be complicated so we need a expert app builder which will link to a website (Only serious people with good credentials). We will print cards with pre-generated QR codes and serial numbers. Every 5 cards will have the same QR code but all serial numbers on card will be different. We will need a Website built that links to the APP for IPHONE and ANDROID apllications. THIS IS THE CHANCE TO DO SOMETHING MEMORABLE.
YOUR JOB. Build an application where somone registers their details which automatically creates them a profile on a website. The Application then asks the user for a serial number found on our cards. Once input they activate 5 cards and the app then allows thenm to record a video on the Iphone or samsung ect. This video will automatically link to the QR code on the card which has already been linked to a URL on our website. This means that the video becomes stored on our website. The user via the APP can changethe video when they want. Once someone has scanned the QR code 5 times the video link is no longer viewable.
Other skills you may need
Wordpress (This could be optional depending on your strategy