Since "Rattail" is more of an umbrella term, it will help to define the applications it provides from an administrator's (or user's) perspective. This page makes such an attempt.
First, a disclaimer of sorts: The real idea behind Rattail is that it contains a shareable, retail-centric codebase which is meant to be consumed by applications which are written with specific organizations in mind. These applications may be written in-house, or custom development services are available also. With this in mind, there aren't very many "out of the box" applications provided by Rattail. This is intentional and will likely be the case for some time.
In fact, even the applications which are currently available are really more like "building blocks" for a larger system of connected applications. For example, you may have the Rattail CE app running on a MC 9090G mobile computer, and a Rattail File Monitor app running on the host (docking) computer. The file monitor may process the scan file for import to another system, or may simply move the file "upstream" to a web server for use with an in-house web app, etc. (What you have the file monitor do with the scan file(s) from the handheld is ultimately up to you.)
Enough disclaimers; on to the applications: