I'm usually all over this type of thing, but there is no edge, so there is no point practicing for the real world dice, or mastering it, we'll be mastering zero edge game.  Aside from that, it looks amazing, simple, and I like how it shows the dollar amount of your bet, allowing to readjust the bet based on price on the fly, without doing any conversions yourself.  If this is solely for practicing and not its own zero edge game, I'd let the user to set their own edge, .5% or 1%, etc, or higher for those that want it.