Emulate Run button in Xcode from the command line

I am looking for a way to create and run my application in a simulator from the command line. I need it to behave the same as when I click Run in xcode.

I can build it using xcodebuild, and I tried using a simulator with the -SimulateApplication option. My application is running, but my tests did not run (as it did when starting with xcode).

I tried the script found here and several other AppleScripts that I found on the Internet. They did not work for me. Commands such as build and cleanup were ignored, while others were errors. Maybe because I use xcode 4. Please help.