This App is for use with "The Grail" by Mike Rose. You must own "The Grail" cardtrick in order to benefit from this App. The instructions for "The Grail" cardtrick will not be explained here and I will be a bit vague as to not give away the secret to anyone not owning "The Grail".
What this App does is eliminate you from having to do any calculations, removing any memory work and allowing you to concentrate on your presentation.