If it doesn't let you launch, you may need to find the app in Finder and open it from the right click menu. Seems that OS X requires you to do this so that it k

If it doesn't let you launch, you may need to find the app in Finder and open it from the right click menu. Seems that OS X requires you to do this so that it knows you explicitly want to launch it. It remembers this after the first launch so you can use it normally afterwards.