Evaluation of Aim to Play, a User-Friendly Digital Application for Teacher Skills Training and Physical Education Activities for 3-5 Grade Students

The goal of this clinical trial is to evaluate the newly developed Pocket PE 3-5 app, designed for use by teachers of 3rd-, 4th-, and 5th-grade students. Researchers will compare teachers and students in classrooms using the Pocket PE app with those in classrooms not using the app. The main question it aims to answer is: • Does the use of the Pocket PE 3-5 app improve classroom teacher PE self-efficacy and high-quality PE teaching behaviors, and promote students' moderate-to-vigorous physical activity participation in PE, as well as PE enjoyment and self-efficacy, compared to teachers who do not use Pocket PE 3-5? Participants will: * Randomly use Pocket PE 3-5 (12 intervention schools) for at least one PE class weekly, or not (12 control schools), for 12 consecutive weeks during the 2025/26 school year. * Teachers will complete short surveys at 0 weeks (pre), 6 weeks (mid), and 13 weeks (post). Teachers in the intervention condition will complete a longer survey at 13 weeks (post-intervention) to provide feedback on the Pocket PE app. A random sub-sample of teachers in the intervention condition will be asked to participate in an exit interview to give additional input on Pocket PE 3-5 after the intervention has been completed. * Students will complete brief surveys after PE classes at pre, mid, and post, and will wear wrist heart rate monitors during observed PE classes at these timepoints to measure their physical activity during PE. We will also evaluate the level of implementation of Pocket PE 3-5 among teachers via class observations and objective data collected by the app.