At the end of Lecture 1, I used an application called Scattered to demonstrate that software engineering is not just about programming and that a software engineer will make use of multiple tools (an IDE and a profiler) when tracking down a problem and may have to re-design a program (in this case converting a single-threaded application to a multi-threaded application) in order to solve that problem.
The Scattered application comes from the excellent book Cocoa Programming for Mac OS X, 4th Edition by the Big Nerd Ranch.
You can examine the source code for this application on Github. The file of interest (the one I featured briefly during the lecture) is called ScatteredAppDelegate.m:
Note: I will NOT be asking questions about this code in homework assignments and/or quizzes. But, if you would like to study these examples in more detail, by all means, please do!