Based on a well known RPN calculator, you need to find its rom file, rename it as 00c.obj, download it in your "Download" directory and then launch the app.
See https://sites.google.com/site/olivier2smet2/home/go1xc
To get the inline help, touch the LCD part of the display
To get the settings menu, long touch the LCD part of the display
9Apps 4.9
