First Round: Telephonic Round. As I was applying as an experienced candidate, the interviewer asked many questions. He almost touched each and every IOS topics. Main topics: Notifications, Database, Concurrency, Autolayouts, Size Classes, Protocols, Enums, Design Patterns, Background processing, In-App purchases, AppStore uploads and many more.
Second Round: Face- to- Face. Again the interviewer asked in-depth questions. Topics: UI, Autolayouts, Social Media Integration, Google APIs , App Distribution via various platforms, optionals and many.