News flash! With the HP app catalog going away, the client may be downloaded either from this site or sourceforge and installed using the webOS Quick Installer. The latest version 0.3.3 mostly fixes a couple of drawing bugs. There is again some movement with this client, so check back regularly for updates.
The webOS RDP client, is a gestures based client that supports Windows 2000 Server through Windows 8. To make the best use of the client it is important to understand both the gestures system, as well as the connection string syntax (to enable sound, or various other options). If this is your first time using the client, please spend a couple minutes and take a look at the gestures and connection string syntax pages.