My app has been banned from the App Store since it's a poker app and the enterprise customers of the Apple App Store doesn't like competition. I have instead chosen to provide the free version of my app as a .ipa file which the user may download and install using the iphone tool "iTools". It worked on my iOS 11.4 iPhone 5s but when trying to install it on a new iOS 11.3 iPhone 7 (or 8. I don't know). The install process ended with an internal error. And the app was not visible on the iphone. Do I have to build a new version for each iphone 4, 5, 6, 7, 8? Or do I have to build a new version for each iOS version 11.2, 11.3, 11.4? I built the .ipa in Visual Studio (Debug mode). I just checked the checkbox "Build IPA", got my file which I was able to install in my iPhone using iTools.