Comment by jiggawatts

Citrix is almost always used to re-host existing applications. I've only ever seen very small utility apps that were purpose designed for Citrix and always as a part of a larger solution that mostly revolved around existing applications.

Note that Citrix or any similar Windows "terminal services" or "virtual desktop" product fills the same niche as ordinary web applications, except that Win32 GUI apps are supported instead of requiring a rewrite to HTML. The entire point is that existing apps can be hosted with the same kind of properties as a web app, minus the rewrite.