A lot of Xcode projects require you to add additional frameworks to link against. Here’s how:
Select the main project listing in the left column.
Select Build Phases from the tabs near the top.
Click the ‘+’ button in the “Link Binary With Libraries” section (you may have to twist it open.
Choose the framework(s) you want to add, and click the “Add” button.
This post is part of the Learn Objective-C in 24 Days course.