Below is a short summary of the procedure and attached is a tutorial from Apple

1.       Prepare a Macintosh computer or VMWare running OSX (OSX is Apple’s operating system)

2.       Install Apple Xcode tool.

3.       Apply for a Developer Certificate ($99/yr) or Enterprise Certificate ($299/yr). https://developer.apple.com/programs/start/ios/

Developer is better for creating apps that go on the Apple store.

Enterprise is better for creating apps that are distributed directly to users through your own Website. 

4.       Learn how to use Xcode to create an IPA file and then create the IPA file.  

5.       Learn how to upload apps to the Apple store or distribute it privately.  

If customer creates their own .IPA file they do not use Appeon Workspace. 

Appeon Workspace is for people who do not want to go through the above procedure to create their own .IPA file.