Thanks for the interest. I will post it publicly soon, but right now it's on my private github. Basically it's a small python app running on a raspberry pi with 2 USB QR scanners. It uses sqlite with a database of QR codes assigned to the students. They wear lanyards with those codes on them. When they start running it logs their start, and every lap they can again. It tracks personal records, total laps, laps per day, and time per lap.

We've received a lot of positive feedback from the kids compared to the old system that was using proprietary software. The problem with that software is it used cell phones for scanning codes, which is very error-prone and takes a long time to register on some phones.