Microsoft Plickers: Immediate feedback on students’ understanding

Plickers is a powerful, simple and time-saving tool that provides teachers with immediate formative assessment data.
I am implementing Plickers with my cycle 2 students during the science classes. 
I ask my students to simply turn their card to the letter A, B, C, or D while I scan their cards through my smartphone camera. Instantly, the students’ answers load right to the screen!