iOS Application Components

Compiled iOS applications live in application bundles. Like their Macintosh cousins, these application bundles are just folders named with an .app extension. Your program’s contents and resources reside in this folder, including the compiled executable, supporting media (such as images and audio), and a few special files that describe the application to the OS. The folder is treated by the operating system as a single bundle.

Application Folder Hierarchy

iOS bundles are simple. Unlike the Mac, iOS bundles do not use Contents and Resources folders to store data or a MacOS folder for the executable. All materials appear at the top level of the folder. For example, instead of putting a language support (.lproj) folder into Contents/Resources/, Xcode places it directly into the top .app folder. You can still use subfolders to organize your project, but these developer-defined folders do not follow any standard.