Mobile clickers are all the rage but they presume that students have mobile devices and that schools will actually allow them to be used. Enter former teacher, Nolan Amy, with a simple, low-tech solution. Give students a physical card with a unique QR code. Each of the four sides of the card represent a different response (A-B-C-D). When the teacher prompts the class with a question, students raise their card in front of a class camera (which can be a webcam or mobile device) that records the responses onto a teacher dashboard. It’s “data collection solved for every classroom that only has one device,” says Amy.

Plickers was part of the Imagine K12 fourth cohort in 2013.