Appendix C. Archiving and Packaging Apps for Development and Testing
Although this book focuses on Objective-C itself, there is no point learning Objective-C if you do not use it at least to build some test code. A key part of development is packaging and distributing the code so that you can run it on various devices and share it with other people.
Xcode has an archiving feature that you use to package your code. You get to it from Product, Archive in Xcode.
By the Way
If you are building an iOS app, you must make certain that your Scheme setting is for an iOS device and not for a simulator. If you are building for a simulator, the Archive command is not availble. In order to build for an iOS device, you must be a registered Apple developer, ...