iOS IPA

When installed on the device, *.ipa is unzipped into a corresponding folder. That’s the contents:

• Payload
• Payload/Application.app
• iTunesArtwork
• iTunesMetadata.plist
• WatchKitSupport/WK

The *.ipa’s Payload is made of:

• MyApp
• Application
• Info.plist
• Launch images
• MainWindow.nib
• Settings.bundle
• Custom resource files

Project folder language.lproj:

• Base.lproj - for storyboards
• en.lproj - for English strings
• de.proj - for German strings

To read.

Info.plist contains configuration information for the application, such as its bundle ID, version number, and display name.

_CodeSignature/ contains a plist file with a signature over all files in the bundle.

Frameworks/ contains the app native libraries as .dylib or .framework files.

PlugIns/ may contain app extensions as .appex files (not present in the example).

iGoat-Swift is the app binary containing the app’s code. Its name is the same as the bundle’s name minus the .app extension.

Various resources such as images/icons, *.nib files (storing the user interfaces of iOS app), localized content (<language>.lproj), text files, audio files, etc.

Data directory:

• Documents/
  • Contains all the user-generated data. The application end user initiates the creation of this data.
  • Visible to users and users can write to it.
  • Content in this directory is backed up.
  • The app can disable paths by setting NSURLIsExcludedFromBackupKey.
• Library/
  • Contains all files that aren’t user-specific, such as caches, preferences, cookies, and property list (plist) configuration files.
  • iOS apps usually use the Application Support and Caches subdirectories, but the app can create custom subdirectories.
• Library/Caches/
  • Contains semi-persistent cached files.
  • Invisible to users and users can’t write to it.
  • Content in this directory is not backed up.
  • The OS may delete this directory’s files automatically when the app is not running and storage space is running low.
• Library/Application Support/
  • Contains persistent files necessary for running the app.
  • Invisible to users and users can’t write to it.
  • Content in this directory is backed up.
  • The app can disable paths by setting NSURLIsExcludedFromBackupKey.
• Library/Preferences/
  • Used for storing properties that can persist even after an application is restarted.
  • Information is saved, unencrypted, inside the application sandbox in a plist file called [BUNDLE_ID].plist.
  • All the key/value pairs stored using NSUserDefaults can be found in this file.
• tmp/
  • Use this directory to write temporary files that do not need to persist between app launches.
  • Contains non-persistent cached files.
  • Invisible to users.
  • Content in this directory is not backed up.
  • The OS may delete this directory’s files automatically when the app is not running and storage space is running low.

Bundle directory:

• AppName.app
  • This is the Application Bundle as seen before in the IPA, it contains essential application data, static content as well as the application’s compiled binary.
  • This directory is visible to users, but users can’t write to it.
  • Content in this directory is not backed up.
  • The contents of this folder are used to validate the code signature.