Apple Software Engineer (Ios Developer) interview questions

After applying online got a mail from HR after 2 months. There were few positions matching my profile as i had iOS experience. Schedules a phone interview giving me a weeks time

Got contacted via email (LinkedIn). Had 2 phone interviews. Very nice people, very professional. Emphasis was more on generic Computer Science questions than specific iOS APIs. Had to solve some specific questions involving efficient use of data structures. Other topics involved multi-threading, Obj-C basics, design patterns, profiling tools. At the end had a chance to ask my own questions. Not much time for this so have them ready.