Hi!
in fact, there is no big difference in building an App for IOS using builder, except we actually need MacOS Virtual machine or Mac.
There are some limitations for the functionality of the mobile app because of IOS. We can't use some options in these apps.
Unfortunately, there is no way to upload your app to Iphone without XCode and paid Developer Account.
Right now we are working on adding the additional modules to explain the building process and IOS installation more precisely.