Xcode only lets me run for an iOS device (no simulator)
Under Your project Build Settings
- select Deployment section
- change iOS Deployment Target to a version iOS 5.0 or less
- now you can go ahead and change the deployment target from device to simulator!
In my case the deployment target was set to version 5.1 and i still am running snow leapord OS with appropriate JARS copied from xcode 4.3 to make it run with a device running iOS 5.1.
However, my simulators do not yet support version 5.1 so till i changed the deployment target to lower version e.g. 5.0 or 4.2 it won't let me run on simulator.