Calculator Pro is described as 'for iPad Free is designed for everyone looking for simplicity and functionality. The app features two calculators sporting elegant interface that won't leave anyone indifferent' and is a Calculator in the Education & Reference category. There are more than 50 alternatives to Calculator Pro for a variety of platforms, including Android, Windows, Mac, Online / Web-based and iPhone. The best alternative is SpeedCrunch, which is both free and Open Source. Other great apps like Calculator Pro are Qalculate! (Free, Open Source), Windows Calculator (Free, Open Source), Numi (Freemium) and Soulver (Paid).
SpeedCrunch is a free, fast, high precision open source algebraic calculator with an intuitive interface and a extensive list of features, including: Unlimited Variables, Syntax Highlighting, Functions, with 'Automagic' Completion, 50 Decimal...
Qalculate! is a multi-purpose cross-platform desktop calculator. It is simple to use but provides power and versatility normally reserved for complicated math packages, as well as useful tools for everyday needs (such as currency conversion and percent calculation).
A simple yet powerful calculator that includes standard, scientific, and programmer modes, as well as a unit converter. It's the perfect tool to add up a bill, convert measurements in a recipe or other project, or complete complex math, algebra, or geometry problems.
Soulver is a smart notepad with a built-in calculator. It gives instant answers to any calculations it finds in your text. It's a better way to work stuff out than with a traditional calculator, and a more lightweight tool for quick calculations than a spreadsheet.
CalcTape is a revolutionary new kind of pocket calculator. With CalcTape, also extensive calculations remain clearly structured. CalcTape makes the arithmetic process visible - you can generate intermediate results and subsequently correct or change all numbers and operations.