Danielle, during development , did you add code to log data in a separate collection when a user log in to track logins, etc ?
I know the Android and Apple stores track jnstalls, etc ... But I'm not aware of any built in code on the Appery side that tracks number of logins .... New device registrations are handled automatically provided you've enabled push notifications .... But even then changes to device information like time zone etc are handled via update by the developer.
Could be wrong and someone from apppery might have different info.
Best
Bruce