Add opacity to your widgets and decrease it every day until their app completely fades away. Set a due date and customize the number of days you offer them until the app is fully vanished.
Faded(
// Due date should be in yyyy-mm-dd format
dueDate: '2021-01-15',
daysDeadline: 12,
child: MyApp(),
)And.... Faded! the app is all gone now..