'RPN is easy' is a simple RPN calculator. This means that the calculator works with an 'Enter' button rather than an '=' button. That may sound difficult, but it's really easy. You enter one number, you enter another number, and then you simply use the '+' button to add them together. That's it!
You can use that result in further calculations. For instance, enter a third number and press '+' again to add it to the previous result. Keep as many intermediate results as you need, all numbers get nicely stacked up, and you can scroll through the stack to view them.
If you need to use a number from somewhere high up the stack, simply select it and press the downward arrow. This will move the selected number down to the bottom of the stack, to make it available for use.
Obviously, the upward arrow works exactly the other way around: select the place where you want to send the bottom number, then press the upward arrow.
And finally, the double arrow is for switching the lowest two numbers.
Have fun!
Improved layout and color scheme
Bugfixes