Not all it appears to be
I downloaded this app to do tire conversions and percentage of difference calculations between stock and aftermarket tires. The app is not what it proclaims to be. It is not user friendly, it’s cumbersome, and more complicated than necessary. I expected table options where I could insert tire sizes in dropdown menus and automated fields. Instead, I got reference tables. There are many free options in the App Store that are more user friendly.