appsync

An .ipa (iOS App Store Package) file is an iOS application archive file which stores an iOS app. Each .ipa file includes a binary and can only be installed on an iOS device. Files with the .ipa extension can be uncompressed by changing the extension to .zip and unzipping.
Most .ipa files cannot be installed on the iPhone Simulator because they do not contain a binary for the x86 architecture, only one for the ARM architecture of mobile phones. To run applications on the simulator, original project files which can be opened using the Xcode SDK are required. However, some .ipa files can be opened on the simulator by extracting and copying over the .app file found in the Payload folder. Some simple apps are able to run on the simulator through this method.
ipa is a de facto format used by Apple and there are no specifications of it. A form of Digital Rights Management exists in the format to control redistribution to a single Apple ID. Prior to iTunes 12.7 (September 2017), users had direct access to ipa files in the form of App Store downloads.

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