No user data is collected by the Scene Sketcher app, other than what Google may undertake in managing Google Play and handling in-app purchases. If you send an email to scenesketcher@gmail.com, it will be read and responded to confidentially.
The Scene Sketcher app does not host advertising and does not collect personal data, so the only information at issue is email correspondence, which will be retained in confidence and not forwarded to any other party.
No user information is shared with others.