In order to compile and submit an iOS build, you must have a Macintosh computer running the most current OS X version and have the most recent version of Xcode installed. You will also need a computer that meets the minimum requirements to run Unity 5, which includes Windows XP SP2+, Windows 7 SP1+, Windows 8+, or Mac OS X 10.8+, and a graphics card that supports DirectX 9.

You will also need a plugin that allows you to access native iOS functions that can handle in-app purchases. In the book, I use IOS Native, which is available through Unity Asset Store.

To only follow the process and not build or submit the game to Apple, you simply need any computer that has the minimum requirements to run Unity 5.