Your data and deleting it
Zill has no accounts, so there is no account to delete and nothing about you is stored on any server.
Deleting everything
Everything Zill keeps (saved places, parking settings, car profile, Shadow Lens scenes, the Sun Diary, streaks, badges and settings) lives only in the app on your phone. Delete the app from your home screen and all of it is gone.
Deleting a part
Saved places and objects can be deleted on the Shade Map, and saved Shadow Lens scenes in Capture, Saved scenes.
Purchases
Your Zill Pro purchase belongs to your Apple Account and is managed by Apple.