This application is to assist you in your pre-flight planning. You can get a estimate of what you useful load and how you should load it. This will make it easier for you when you do your preflight W&B calculation. To change your empty weight and empty moment just click the dark area at the top and a keyboard will appear to change what you selected.
If you experience any malfunction or find any bugs please let us know ASAP so we can send Apple an update.