Hack to choose the displayed carrier name in the iOS simulator, now working in iOS 5 and iOS 6 (with different carrier names)

XCDFakeCarrier.m

//
// Copyright (c) 2012 Cédric Luthi / @0xced. All rights reserved.
//

#if TARGET_IPHONE_SIMULATOR

#define ITEMISENABLED_LENGHT_IOS5 23
#define ITEMISENABLED_LENGHT_IOS6 24
#define STATUSBARBATATYPEENCODING_IOS5 "^{?=[23c][64c]ii[100c]"
#define STATUSBARBATATYPEENCODING_IOS6 "^{?=[24c][64c]ii[100c]"
#define FAKECARRIER_IOS5 @"iOS5"
#define FAKECARRIER_IOS6 @"iOS6"
#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v)  ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)

static NSString * FakeCarrier = FAKECARRIER_IOS6;

#import <objc/runtime.h>

typedef struct {
	char itemIsEnabled[ITEMISENABLED_LENGHT_IOS6];
	char timeString[64];
	int gsmSignalStrengthRaw;
	int gsmSignalStrengthBars;
	char serviceString[100];
	// ...
} StatusBarDataIos6;

typedef struct {
	char itemIsEnabled[ITEMISENABLED_LENGHT_IOS5];
	char timeString[64];
	int gsmSignalStrengthRaw;
	int gsmSignalStrengthBars;
	char serviceString[100];
	// ...
} StatusBarDataIos5;

@interface XCDFakeCarrier : NSObject
@end

@implementation XCDFakeCarrier

+ (void) load
{
	BOOL success = NO;
	Class UIStatusBarComposedData = objc_getClass("UIStatusBarComposedData");
	SEL selector = @selector(rawData);
    SEL fakeSelector;
    const char *statusBarDataTypeEncoding;
    if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"6")) {
        fakeSelector = @selector(fake_rawData_iOS6);
        statusBarDataTypeEncoding = STATUSBARBATATYPEENCODING_IOS6;
        FakeCarrier = FAKECARRIER_IOS6;
    } else {
        fakeSelector = @selector(fake_rawData_iOS5);
        statusBarDataTypeEncoding = STATUSBARBATATYPEENCODING_IOS5;
        FakeCarrier = FAKECARRIER_IOS5;
    }
	Method method = class_getInstanceMethod(UIStatusBarComposedData, selector);
	Method fakeMethod = class_getInstanceMethod(self, fakeSelector);

	if (method && strncmp(method_getTypeEncoding(method), statusBarDataTypeEncoding, strlen(statusBarDataTypeEncoding)) == 0)
	{
		success = class_addMethod(UIStatusBarComposedData, fakeSelector, method_getImplementation(fakeMethod), method_getTypeEncoding(fakeMethod));
		fakeMethod = class_getInstanceMethod(UIStatusBarComposedData, fakeSelector);
		method_exchangeImplementations(method, fakeMethod);
	}
	
	if (success)
		NSLog(@"Using \"%@\" fake carrier", FakeCarrier);
	else
		NSLog(@"XCDFakeCarrier failed to initialize");
}

- (StatusBarDataIos6 *) fake_rawData_iOS6
{
	StatusBarDataIos6 *rawData = [self fake_rawData_iOS6];
	strlcpy(rawData->serviceString, [FakeCarrier UTF8String], sizeof(rawData->serviceString));
	return rawData;
}

- (StatusBarDataIos5 *) fake_rawData_iOS5
{
	StatusBarDataIos5 *rawData = [self fake_rawData_iOS5];
	strlcpy(rawData->serviceString, [FakeCarrier UTF8String], sizeof(rawData->serviceString));
	return rawData;
}

@end

#endif

This works perfectly. Thanks for providing this!