In this chapter we’re going to start with an existing, very old iOS project I wrote around 2009. It’s a very simple slot machine app that came out for the second-generation iPhone, the iPhone 3G. In fact, at that time there was no iOS. Apple called the operating system iPhone OS, even though it worked on the iPod Touch device as well. There was no iPad released yet.
You’re asked to add features to an existing Objective-C project that would be better served using the Swift language because of its modern features, or to simply update the project.