The Legendary 67 revives the spirit of the indeed legendary hp67, one of the first handheld, scientific and programmable calculators.
Calculations are done step-by-step using reverse Polish notation (RPN), which is very similar to calculating with pen and paper. This gives you full control and lets you spot mistakes early rather than later. In addition it is much simpler than using an algebraic calculator while using less keystrokes all at the same time. Last but not least, RPN makes it super easy to create your own programs.
Creating programs is exactly like using the calculator, so there is no need to learn any programming language. Simply put the calculator just records exactly the keys you typed and can replay them on demand. Through a small set of nifty features, like conditions, subroutines and flags a vast set of powerful programs is possible. You can program everything from simple snippets like the Pythagorean theorem, implement matrix algebra and even create games.
The calculator comes equipped with a handful of useful programs and you can easily create your own. Each program is stored on a virtual magnetic card, with fully customisable labels and descriptions.
Now the best part, the app is completely free and does not include any advertisements.