Xcode is used to develop iOS apps and you need a Mac computer and a free Apple ID to download and install it. If your Mac is relatively older and with OS X El Capitan (version 10.11.6), you can download Xcode 8.2.1 at https://developer.apple.com/download/more. Or if you have macOS Sierra (version 10.12.6) or later, installed, you can download Xcode 9.2 or 9.3, the latest version as of May 2018, from the preceding link. All the iOS apps in the book have been tested in both Xcode 8.2.1, 9.2, and 9.3.
To install Xcode, simply double-click the downloaded file and follow the steps on the screen. It's pretty straightforward. You can now run apps on the iOS simulator that comes with Xcode or your own iOS device. Starting Xcode 7, ...
