You can use as many devices as you need. Students may scan at any device, and the data will sync to the appropriate account in the database.
However, to make sure students hear accurate lap counts on the course, we recommend that runners be assigned to a designated device. And remember, It is always a good idea to sync the devices before and after the scan sessions.
Note: If you have multiple teachers or volunteers that need to log into the app, you can create a shared user account for the school that everyone can use.