Files hold lists and lists hold items. For instance, the My Lists file that appears under Custom Lists when you first install ListPro on your iPhone, holds a number of Lists. Each of these lists have items in them.
With files, you can organize your lists in a way that suits you. For instance, you might want a file for all your work lists and another file for all your personal lists.
Follow these steps to create a new file for custom lists:
At the Home view, touch Custom Lists.
Touch the plus button.
Enter a name for the file.
Touch the Save button.
Custom List Files Created on the Desktop
If you create your custom lists files in ListPro on the Windows PC and want to use that file on your iPhone, make sure you've selected the Enable sync for this file menu item in the Synchronize menu on your Windows PC. If you don't enable sync for a file, it won't synchronize with your iPhone.