added global unique identifier for tracking between different apps

Classes/UIDevice+IdentifierAddition.h

@@ -11,6 +11,23 @@
 
 @interface UIDevice (IdentifierAddition)
 
+/*
+ * @method uniqueDeviceIdentifier
+ * @description use this method when you need a unique identifier in one app.
+ * It generates a hash from the MAC-address in combination with the bundle identifier
+ * of your app.
+ */
+
 - (NSString *) uniqueDeviceIdentifier;
 
+/*
+ * @method uniqueGlobalDeviceIdentifier
+ * @description use this method when you need a unique global identifier to track a device
+ * with multiple apps. as example a advertising network will use this method to track the device
+ * from different apps.
+ * It generates a hash from the MAC-address only.
+ */
+
+- (NSString *) uniqueGlobalDeviceIdentifier;
+
 @end

Classes/UIDevice+IdentifierAddition.m

@@ -22,6 +22,9 @@ - (NSString *) macaddress;
 
 @implementation UIDevice (IdentifierAddition)
 
+////////////////////////////////////////////////////////////////////////////////
+#pragma mark -
+#pragma mark Private Methods
 
 // Return the local MAC addy
 // Courtesy of FreeBSD hackers email list
@@ -71,6 +74,10 @@ - (NSString *) macaddress{
     return outstring;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+#pragma mark -
+#pragma mark Public Methods
+
 - (NSString *) uniqueDeviceIdentifier{
     NSString *macaddress = [[UIDevice currentDevice] macaddress];
     NSString *bundleIdentifier = [[NSBundle mainBundle] bundleIdentifier];
@@ -81,4 +88,11 @@ - (NSString *) uniqueDeviceIdentifier{
     return uniqueIdentifier;
 }
 
+- (NSString *) uniqueGlobalDeviceIdentifier{
+    NSString *macaddress = [[UIDevice currentDevice] macaddress];
+    NSString *uniqueIdentifier = [macaddress stringFromMD5];
+
+    return uniqueIdentifier;
+}
+
 @end

README

@@ -2,7 +2,8 @@ Apple stopped supporting a unique identifier for iOS. This source code solves th
 
 What you need to do:
 - copy NSString+MD5Addition and UIDevice+IdentifierAddition to your project.
-- use [[UIDevice currentDevice] uniqueDeviceIdentifier] to retrieve the unique identifier.
+- use [[UIDevice currentDevice] uniqueDeviceIdentifier] to retrieve the unique identifier
+or use [[UIDevice currentDevice] uniqueGlobalDeviceIdentifier] to retrieve a global unique identifier (used for tracking between different apps).
 - have fun and follow twitter.com/gekitz ;)
 
 //Thanks to Erica Sadun for her UIDevice+Hardware Addition (used for the mac address retrieval).

UIDeviceAddition/UIDeviceAdditionViewController.m

@@ -31,12 +31,23 @@ - (void)didReceiveMemoryWarning
 - (void)viewDidLoad{
     [super viewDidLoad];
 
-    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(10, 200, 300, 100)];
+    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(10, 100, 300, 100)];
     label.numberOfLines = 0;
-    label.text = [[UIDevice currentDevice] uniqueDeviceIdentifier];
+    label.textAlignment = UITextAlignmentCenter;
+    label.text = [NSString stringWithFormat:@"Unique Device Identifier:\n%@",
+                  [[UIDevice currentDevice] uniqueDeviceIdentifier]];
 
     [self.view addSubview:label];
     [label release];
+
+    label = [[UILabel alloc] initWithFrame:CGRectMake(10, 210, 300, 100)];
+    label.numberOfLines = 0;
+    label.textAlignment = UITextAlignmentCenter;
+    label.text = [NSString stringWithFormat:@"Unique GLOBAL Device Identifier:\n%@",
+                  [[UIDevice currentDevice] uniqueGlobalDeviceIdentifier]];
+
+    [self.view addSubview:label];
+    [label release];
 }