You can use:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSDictionary *defaultAsDic = [defaults dictionaryRepresentation];
NSArray *keyArr = [defaultAsDic allKeys];
for (NSString *key in keyArr)
{
NSLog(@"key [%@] => Value [%@]",key,[defaultAsDic valueForKey:key]);
}