A free app for Android, by Avec Dev.
The Box Check-In app is an integrated tool for the booking of fitness classes.
The first thing you will need to do is register on the Box Check-In website, so you can book classes and receive the confirmation.
Once you have done that, you will need to download the app and register your Box account with the username and password that you have registered on the website.
The app will send you an email confirmation, so you just need to click on the link to confirm your registration.
After that, you will be able to see the classes that are available on your area and you will be able to book them.