PCalc is described as 'The powerful choice for scientists, engineers, students, programmers, or indeed anybody looking for a feature rich calculator. It includes an optional RPN mode and multi-line display, a choice of button layouts, an extensive set of unit conversions and constants, a' and is a Calculator in the education & reference category. There are more than 100 alternatives to PCalc for a variety of platforms, including Android, Windows, Web-based, iPhone and Mac apps. The best PCalc alternative is Wolfram Alpha, which is free. Other great apps like PCalc are SpeedCrunch, Fossify Calculator, Qalculate! and OpenCalc.
full with functions, and logical buttons.