Had a phone screen for iOS Engineer. Interviewer first asked me to introduce myself and to tell them about my recent project. Then I was asked two behavioral questions.

1. Tell me about a time when one of your peers was in a difficult position and what did you do to help him/her?
2. Tell me about a time when you compromised quality over delivery? What did you learn? In hindsight what could have you done differently?

Then I was asked to desing and CODE an API similar to GCD (Grand Central Dispatch) in iOS.

I was surprised with the question and went blank for a moment as I was interviewing for entry to mid level position. Anyway, I tried my best but was not able to produce anything meaningful. Personally, I feel it's a little unfair to ask such a question in phone screen.