ABContactsHelper modification to remove linked contacts from "all contacts" list. Preliminary testing shows the end result mimics the list in the Contacts app. Note: I have not determined if the data returned for each ABContact includes data from linked records. I suspect it does not. Most likely, the data access methods will need to be modified…

gistfile1.m

/* 
	This modification extends Erica Sadun's ABContactsHelper.m

	https://github.com/erica/ABContactHelper

	Feedback and performance suggestions welcome!

	Edit 1/29/13: refactor to avoid calling ABPersonCopyArrayOfAllLinkedPeople() multiple times for same person.
		Testing shows 5% performance improvement (811 total records = 249 unlinked + 562 linked), 
		3 run average, looping through code 10 times each run, in simulator.

*/

+ (NSArray *) contacts {
    ABAddressBookRef addressBook = [ABStandin addressBook];
    NSArray *thePeople = (__bridge_transfer NSArray *)ABAddressBookCopyArrayOfAllPeople(addressBook);
	
    NSMutableArray *contactArray = [NSMutableArray arrayWithCapacity:thePeople.count];
	NSMutableArray *linkedPeopleArrays = [NSMutableArray arrayWithCapacity:0];
	
    for (id person in thePeople) {
		NSArray *linked = (__bridge_transfer NSArray *)ABPersonCopyArrayOfAllLinkedPeople((__bridge ABRecordRef)person);
		
		if ([linked count] <= 1) {
			ABContact *contact = [ABContact contactWithRecord:(__bridge ABRecordRef)person];
			[contactArray addObject:contact];
		} else {
			[linkedPeopleArrays addObject:linked];
		}
	}
	
	NSMutableArray *peopleUsed = [NSMutableArray arrayWithCapacity:0];
    for (NSArray *linkedPeople in linkedPeopleArrays) {
		
		NSInteger personId = NSIntegerMax;
		id personUsed = nil;
		
		for (id linkedPerson in linkedPeople) {
			
			if ([peopleUsed containsObject:linkedPerson]) continue;
			
			ABRecordID recordID = ABRecordGetRecordID((__bridge ABRecordRef)linkedPerson);
			if (recordID < personId) {
				personId = recordID;
				personUsed = linkedPerson;
			}
			[peopleUsed addObject:linkedPerson];
		}
		
		if (personUsed != nil) {
			ABContact *contact = [ABContact contactWithRecord:(__bridge ABRecordRef)(personUsed)];
			[contactArray addObject:contact];
		}
	}
	
    return contactArray;
}