I found a great app called Cardio. The app takes a scan of the users face and determines heart rate just by scanning the reflection. I was skeptical but I have used it again and again and it is right on every time. The app costs 1.99 but it is well worth it. Think of all the time that you will save by not having to put a strap on a student in order to track their heart rate.

It is funny that you ask this. Last November 2014, our department completed Professional Development that required us to research effective applications for classroom/physical activity use. We found a bunch of different ones and really came to the conclusion that the teacher has great individual freedom to find what works with the content being taught.

Some of the applications we found useful are listed as follows:
Run Keeper, Pacer/Pedometer, Gym Friend, Daily Workouts, MyFitnessPal, Fooducate, Nutrition Quiz, Kid Recipes, AddressStress, Guided Mind, SAM, Relax Melodies

There are many others out there that even include using the camera in your phone to measure your heart rate! Technology is crazy! We just need to figure out how to use it to our advantage within our curriculum.