*** 24 hour cancellation period ***Part of the Silverglance Software suite of apps, Vertigo will convert between approximately 350 general and engineering units in over 35 categories of measurement.Conversions also include numbering systems (decimal, binary, hexadecimal, roman numeral), sheet metal gages and fractions. A scientific calculator is also included.Extended cancellation period – contact us by email within 24 hours of downloading the app if you are unhappy with your purchase.