There are two free apps that every teacher with a smartphone should get today: Photomath and Plickers.
Photomath is able to provide answers to complex math equations just by scanning the equation with a smartphone camera. It is currently available only for Apple and Windows devices, but an Android version is expected in 2015.
Photomath is able to break down each step taken in an equation to derive the correct answer, which means students can quickly see how to solve tricky math problems. This means students have an additional avenue to see how equations are solved, but students also have an additional way to cheat on their homework.
Plickers is the best free formative assessment tool for an entire classroom I have ever seen.
Plickers works because it engages the entire class with individual student codes that the teacher can quickly scan with a smartphone app. The way a student holds his or her paper will register the student’s response of either A, B, C, or D. A teacher can scan an entire classroom in less than ten seconds from the front of the room with the app and the results will show up instantly for the class to see (if connected to a projector). Students can see if their responses have been registered and put their codes down. The teacher can see if all of his or her students participated, which is huge. If a teacher has a smartphone, this is a must-have app. It is the most economical method I have ever seen for this type of formative data collection. This app has the potential to revolutionize how teachers approach bell ringers, exit slips, and formative assessment.