Wow, the dice-rolling looks as good as MotionX's -- but with the added element of "3D viewing" once it's rolled, and a better response to how you're actually shaking. VERY cool!
It may not be as slick and polished as MotionX's, but it allows for a ton of customization of dice (the number of dice and how many sides at least -- though changing the LOOK of the dice would be cool too, if added in an update). I can't believe people are actually giving some negative reviews simply because there's the free MotionX version, when they clearly don't understand how much more advanced this is in terms of die customization. Morons! And why are people upset this is just a dollar? I actually think it could be more.
One thing I'd change is the input system for the dies. While it's probably the quickest way to get the dice you want, it's not the most intuitive or clear way to do it. I would prefer having a screen that had a set number of lines for each die, and each line was a scrolling dial segmented for each feature: number of dice, dice type, and then maybe another customization like color, and whatever else you might want to throw in. Have a button you press next to each line that locks your choices into place or something, and then you have it! With a more polished look, and a better input system, you could easily sell this for up to $4-5 and people would buy!