If you ever find yourself doing iPhone consulting then you will probably need to know how to create an .ipa file. An ipa file makes it easy to distribute apps to people. It’s part of the Ad Hoc app distribution process. iTunes Mac users don’t require an .ipa file to install an Ad Hoc app. They can simple drag the app and the provisioning profile into iTunes. On the other hand, Windows users will need an .ipa file in order to install the app on their device. The great thing about distributing via an .ipa file is Mac and Windows users can install the app in iTunes.