The latest version of Ratio Calc for the iPhone/iPod Touch has recently been released and is in the App Store. The app is now multi-lingual and currently supports English, German, Spanish and Italian.
Ratio Calc! is a quick and easy tool for radio control car racers to use trackside. Gear ratios are a vital part of R/C racing and knowing your final drive ratio (FDR) is very useful for both comparison with other racers and tuning purposes.