Unity3D trampoline, yet 4.2.2 does not properly specify CFBundleIconFiles's setting which is needed to support iOS7's icon images. Run this python script to update that. Note that all icon files are should be under the same directory where .xcodeproj xcode project file is.

update_icon.py

#!/usr/bin/python

#
# Run this script to add various icon files to info.plist 
# which is needed to support iOS7 icon image files.
#
# (C)2013 Kim, Hyoun Woo
#

import sys
import os
import plistlib

def updateCFBundleIconFiles(xcode_project_path):
	info_plist_path = os.path.join(xcode_project_path, 'Info.plist')
	pl = plistlib.readPlist(info_plist_path)

    # all these icon files should be under target directory.
	new_settings = [
		'Icon.png', 
		'[email protected]', 
		'Icon-72.png', 
		'Icon-76.png', 
		'Icon-120.png', 
		'Icon-144.png', 	
		'Icon-152.png'	
	]	

	pl["CFBundleIconFiles"] = new_settings;

	plistlib.writePlist(pl, info_plist_path)

    # for the debugging purpose
	#print pl


if len(sys.argv) < 2:
	print "Missing target directory. Specify xcode project path for target directory.\n"
	print "Usage: python update_icon.py [absolute path where xcode project file is]\n"

targetDir = sys.argv[1]

updateCFBundleIconFiles(targetDir)

print "Done update CFBundleIconFiles in info.plist file.\n"