FunctionCalc is a powerful yet user-friendly calculator app available for iPhone users. In addition to basic arithmetic functions, this app offers a range of advanced features that set it apart. Users can access the latest exchange rates for 171 currencies, perform operations on time-formatted numbers like "3:15", and directly convert units of measurement across various categories including currencies, weights, volumes, and temperature.

Moreover, FunctionCalc includes pre-programmed complex mathematical formulas with text prompts for easy data input. It also features eight customizable buttons that can be set for quick access to frequently used formulas and conversions. This app proves to be particularly useful for travelers dealing with foreign currencies and measurement systems, ensuring quick and convenient conversions even without internet connectivity.