The FindMyShadow iOS app does not communicate any user data to any third parties over the internet. The only use of the internet is for the storage of scene data into the user's personal iCloud storage area and for the user-triggered transmission through the sharing sheet (for example as an email attachement).
The use of location services is purely for the purposes of placing the map center at the user's location for convenience when building a scene based on current surroundings or when using the compass feature. This location is not transmitted nor stored other than in the settings for any given scene document, which is stored and shared only as prescribed by the user, as above.
Access to the camera roll is only required for selection of a background image for the scene or for storing individual snapshot images to the camera roll. Background images selected are then stored in binary form within the scene document such that the document is unaffected when moved and copied away from the initial device on which it is composed(for example to / from iCloud storage or transmitted as an email attachement).