I posted a blog post a few weeks ago about an experience I had interviewing at a rather large and well known company that had a white board interview where I was being asked to implement a linked list in Java.
I expressed that I felt this was a useless task.
I got a lot of pushback from people on Twitter about this. A lot of older programmers chastised me that you can’t be a great programmer if you don’t understand data structures and algorithms. I tried to make the point that if you are an iOS developer that most of your job is to have knowledge of the iOS frameworks and that the language is secondary. Someone who had never owned a Mac or opened Xcode could theoretically get a job as an iOS developer.
Janie sparkled a conversation about this. I'm on her side (not that anyone's taking sides, anyway).
I remember when I interviewed at TopTal for an iOS Developer position, and they had me writing algorithms in C. A company that posts about what to ask developers in iOS interviews.