I have double checked with the dev team and there should be nothing to worry about

As Monte has mentioned, we have previously provided support for our users to build using older revisions of Xcode but with this announcement, you must build your LiveCode applications against XCode 5 to have them accepted into the iOS store.
The only side effect that this could have, again as Monte mentioned, is needing to upgrade your O/S too at least Mountain Lion and use a version of LiveCode that supports Xcode 5 (6.1.2+)
Kind Regards,
Neil Roger
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RunRev Support Team ~ http://www.runrev.com
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