You can see features description of RapidFlow at https://secure.unirgy.com//products/urapidflow/#tab-about
Standard version of RapidFlow can mport/export any standard product attribute defined in Magento's attributes section. It can also set product's type, attribute set, website and categories.
With standard version you can import base product image, small image and thumbnail - these are standard attributes - you cannot import gallery images.
In addition to standard version, pro gives the ability to import category data, EAV configuration and Product extras.
Category import/export is pretty much the same as standard Product import, but for categories. You can import any available category attribute. You cannot import url_path directly since it is used as category identifier. If imported category has new url_path value, the result is new category.
EAV allows to import/export EAV configuration. This includes attributes, attribute sets, attribute groups, etc.
Product extras import/export include - gallery images, deleting products, associating and rearranging products with categories, configuring complex products (configurable, grouped, bundled, etc.), tier and group pricing, custom options.
For list of all available formats of Pro addon see uRapidFlowPro Fixed Row format