In your search results or on the title details page, tap to sample a title. When you reach the end of a sample, you'll have the option to borrow or place a hold with a tap.
If you'd like to create a category for a title or remember it for later, tap Add to List from your search results, title options, or the title details page. Then add your book to a wish list or customize your own.
Your lists are discoverable and manageable on the shelf tab.