Its called Forzatune Premiere. Its $1.99 on the App store for the Iphone or Itouch. The developers worked with Feuerdog (the guy who created the calcs that almost everyone uses to set up the base tune) to create this app. It basically uses all of his different calculaters to set your car up. You just input the different vehicle stats and it does all the equating for you. This would be useful if your computer was in a different room than the 360 or if you just didnt like figuring it all out yourself. Figured I would mention this. I have not downloaded it but it does look like it works wonders. Just like his online calcs.
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-TahHeels (Bryce) (Nub) (Lover Boy)
IFCA #345