Once you have unpacked the files in this archive please ensure that you have not placed the folder in your downloads directory. 
Please move the folder to your desktop as running the launcher from your downloads directory will cause it to be quarantined and the simulator will fail to run correctly.

In order to open the launcher you may find that when you double click it that you get information messages such as the app is from an unknmown developer or unable to be opened.
These are just due to your OSX security settings - you can overrirde these by the following method:

Right click the launcher and from the popup menu select open. A dialog will appear, click cancel in this dialog.
Now right click the launcher again and from the popup menu select open, you will get a different dialog and select the button to open the application.
You can also use ctrl+click on the launcher and select open - this has the same effect and will put an exception in your security settings automatically.


If you still cannot open the app, then do the following ... 
Open System Preferences.
Go to Security & Privacy and select the General tab.
If you’ve been blocked from opening an app within the past hour, this page will give you the option to override this by clicking the temporary button ‘Open Anyway’.
You’ll be asked one more time if you’re sure, but clicking Open will run the app.