Oh, and if anyone is still having trouble with iTunes, I should mention that IPhonePackager.exe can also install ipa files onto an iOS device. I just tested it and it works.
You can find it in your main Unreal engine folder:
\\UE_4.xx\Engine\Binaries\DotNET\IOS\IPhonePackager.exe
It runs as a GUI if you click on it, but can also be run as a command line with correct parameters for automation.