I'm a Windows user and don't know anything about Macs. Now I have to create a web app for iPhone (it just opens a website inside an app).

I tried installing Xcode 5, but it's not compatible with OS X 10.8.4. I think I have to download Xcode 4, but I can't find it anywhere?

How do I install Xcode on OS X 10.8.4?

(I can't update this OS X because the Mac is not mine.)