Q:

Will I be able to code/publish iOS and Android apps in Mountain Lion using React Native framework?

I'm starting to learn React Native and I'd like to NOT use Create React Native App to code for Android and iPhone because it seems I'll lose some part of the "fun".
In order to do that, it seems I need to use a Mac OS to code, or at least test on iPhone.
MacBooks are out of my budget at the moment, and download from internet is not an option, so the only option, that seems quite right, is to virtualize a Mac OS, but the latest available OS to buy is Mountain Lion.
Will I be able to code React Native apps on Ubuntu and test/publish on iPhone using Mountain Lion in a VM? Thanks in advance!

A:

I doubt it. You need a recent Mac OS/Xcode to create apps for distribution on the App Store.
From: https://developer.apple.com/ios/submit/

Update your version of Xcode to the latest release of Xcode 9 available on the Mac App Store, which includes the iOS 11 SDK, and build your apps. Starting July 2018, all new iOS apps and updates submitted to the App Store must be built with the iOS 11 SDK.

As Mountain Lion is version 10.8.x, its unlikely you'll be able to run Xcode 9 which needs 10.12+ :
See the linked answer to the post on How do I install Xcode 9/10 without updating macOS?
Apple has traditionally forced new/updated apps to use the latest SDK which itself only supports recent version of Xcode which can only be run on recent version of Mac OS.

