Playground gives families the ability to check their students in & out with a private PIN code, even without the app. Centers can offer their own device used as a check-in/out kiosk and a Guardian just has to know their private PIN code to use it.
Here is a walkthrough on how to locate your Family PIN code in the app. If you do not remember your code, please ask an administrator for it (teachers do not have access).
Here is a second quick walkthrough for how to check your student in or out.