How do I transfer Phonegap app to my iPhone Apple removed the ability to transfer apps to your iPhone via iTunes, which is the workflow I was using before.

What is the correct way to do it now? Is there some way in Xcode? I typically use a Windows machine for development (but have a Mac for certificate signing and other good stuff that Apple requires), so I'd prefer to not have to transfer my app over to the Mac machine in order to transfer it to my phone, but if I have to do that, I'm willing to.

What is the current workflow?
The easiest way is using a Mac.  Xcode (using the Devices window) can install ipa files on developer registered iOS devices.  The Apple Configurator 2 app (available from the Mac App store) will also allow you to select ipa files and install them (assuming they are provisioned correctly) on iOS devices.

Without a Mac, it may be possible to use an https service that allows downloading a correctly provisioned app (Ad Hoc or Enterprise) using a wireless installation manifest.