Keep Old Task Shifts
If you set this to 'Off' then deleting a task from the current task list also deletes all shifts for that task. If this is set to 'On' then the shifts will not be deleted.
Shake To Sort
This allows you to change the sort order of the shifts in a report by shaking your iPhone / iPod Touch. Turning this off will set the sort order to the last one selected (see Reports).
Warning Pop Ups
These give you warnings. For example, when you go to delete a task, all the shifts for that task might be deleted. If you prefer, you can turn these off. Careful though!