Here's how to configure Citrix v6.5 Pre-Launch or Instant App Access.
Login to your XenApp server and open Citrix AppCenter.
In Applications view right click on the application that you want to configure for pre-launch and select Other Tasks - Create pre-launch application.
You will notice that a new application will be created as in the picture below:
Have in mind that Application settings for Pre-Launch application are just copied from the Published Application. So, if you change anything for the Published application, you will also have to change this for the Pre-Launch application or just re-create Pre-Launch application.
To make sure this is working, try to login with test user and once you login to Web Interface server, you should automatically see a newly created session for Pre-Launch application.