I'm sorry, I don't see where this KB article offers a solution. It only describes each connection type.
On the iOS PocketCloud App, I have multiple Windows 8 machines that shows up on the Auto Discovery list as "connected" for a Remote Shadowing (VNC) connection. So the only credential will be the password, which I would've provided in the TightVNC configuration. When I try to connect to these machines, with the configured VNC password, I get an invalid credentials message.