UPDATE @ 3:30pm PST 11-30-2012: /blogs/2012/11/30/update-on-ios-receiver/
Receiver for iOS version 5.6.3 was released on November 28th into the App Store. On release, several customers reported an issue found only in the published release. The Citrix engineering team is researching the issue, working with the Apple team.
To limit the exposure to the customer base, the Receiver for iOS is temporarily removed from the App Store.
Please watch here for updated information.
Thank you for your feedback and patience while we resolve this issue and repost to the App Store.