My students LOVE to get to use the iPads any time of the day. This allows my student the ability to self-check using a free QR code reader.
To access the QR code on each card you will need to download a free QR reader on your iPad, iPhone, iPod touch, or laptop (any of these devices, as long as it has a camera, will work.)
There are many free QR Code reader applications. Search for them at the app store and choose the one that best fits your classroom needs.