I'm investigating why the download size reported by the App Store (shown in an alert when downloading an app on low data mode) is a larger size than I get locally.
I've copied the example from https://developer.apple.com/documentation/accelerate/compressing_file_system_directories to compress my already thinned .app with LZFSE. The resulting file size is about 10MB smaller than what I see on the app store. However, if I do this same process for an app that has a binary of about the same size, but fewer resource files in the app bundle, my local archive is within 1MB of the App Store download size.
The app thinning report built into Xcode seems to have similar inaccuracies with app bundles containing many files.
I know the app store builds have additional code signing and encryption, but this is only a problem with apps that contain lots of files (specifically localizable strings) and isn't much of an issue with apps that are mostly a binary file. Are there any other differences between what is downloaded on the app store and my local .app that could cause the larger app store download size?
Also, is the App Store using LZFSE or another algorithm like GZIP?
