IOS Simulator installed apps location in Xcode 4.3.1

• Download xcode_3.2.6_and_ios_sdk_4.3.dmg (note - you need a developer account to access this software. I have instead linked to an open-to-the-public Apple discussion that contains the direct download link
• Mount the .dmg file
• Inside the disk image there is an invisible "Packages" folder. To open it select "Go to folder..." command from Finder menu bar and digit the path "/Volumes/Xcode and iOS SDK/Packages/"
• Now double-click "iPhoneSimulatorSDK4_2.pkg"
• Click into the destination disk and a button "Select folder..." will be revealed
• Click the above button and select your "Developer" folder
• Install the package, and Restart Xcode.

This will install the Simulator 4.2 SDK (both iPad and iPhone) inside the folder "/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/"

Now inside XCode 4.2 you can select this simulator from the menu.

Bye.

I would leave the simulator in the Xcode package, but drag it to your dock to easily launch it. Or make an alias to it and place that alias in what ever spot you want to launch simulator from.