When using Chrome it is normal to be prompted for credentials when you launch the first RemoteApp. After you have at least one RemoteApp running you may launch additional RemoteApps without being prompted again. One of the benefits of using Internet
Explorer is that you do not have this second credential prompt.
In the future I recommend you ask questions relating to Remote Desktop Services over in the RDS forum:
Microsoft is conducting an online survey to understand your opinion of the Technet Web site. If you choose to participate, the online survey will be presented to you when you leave the Technet Web site.