The app doesnt take things like splash damage into account. This has been tested, as best as I can tell, only for 1 on 1 matches. A more sophisticates engine that simulated units in 2 dimensions (for calculations, not visually, of course) would be much better. Even the horribly limited army features will be grossly inaccurate most of the time. A simple and important test, like seeing how well a queen could fend off a banshee, is broken because the simulator doesnt know queens have anti air. Id love an app like this, but it needs a lot of work and a totally redone engine.
Captain Hammer about Simulator for Starcraft 2 Lite