>I have not seen any software emulators run lately, only early ones that gamers used to run games. The best emulation I have seen is a hackintosh. This is a proper OS X install on PC hardware. You have to be somewhat careful of the PC hardware, but most will now run OS X. If you don't have a spare box lying about, you can install it in a VirtualBox. The best install is with the UniBeast method and it installs Yosemite. Lifehacker usually has the best info on this. You will need access to a Mac to download a copy of OS X 10.10.
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>That said, you should understand that these installs modify OS X to allow the install and no doubt violates the license. You aren't paying for OS X, another ethical challenge. Do NOT trust any of the complete hacks that also contain OS X, they tend to contain all sorts of mischievous items. The best hacks just create an installation environment for a proper OS X install. XCODE should run without any problems, of course you will have to establish a Mac account to download the software.

I was mostly looking for the app only related software allowing to build apps from Windows. We discussed this recently and a few were suggested.