What is the (file) format of iOS/iPhone apps?

Question

I know that Android apps are packaged as *.apk files, but I have no idea in which way an iOS/iPhone app is stored?

Assuming that iOS apps need to be developed and up- and downloaded to the apple App store I assume that the app is stored as a file. Which format does this file have?

Answer 1

An .ipa file is an iOS application archive file which stores an iOS app. Each .ipa file includes a binary for the ARM architecture and can only be installed on an iOS-device.

.ipa (file extension)

Answer 2

.ipa file extension is used for Apple iOS application file and .ipsw file extension is used for iPhone, iPad or iPod Touch iOS software firmware update file.

Other file extensions or file formats developed for use with Apple iOS .aee , .applesyncinfocpbitmap , .cpbitmapdfu , .dfuimg3 , .img3ios , .iosipb , .ipbipcc , .ipccithmb , .ithmbk48 , .k48m4r , .m4rmapsdata , .mapsdatambdb , .mbdbmbdx , .mbdxmdinfo , .mdinfometriclog , .metriclogmobileconfig , .mobileconfign81 , .n81n88 , .n88n90 , .n90n90ap , .n90apn92 , .n92provisionprofile , .provisionprofilesinf , .sinfsmil , .smilsupp , .supp_ipod_control , ._ipod_control