Free42

I have been using ist for years!

I am a big fan of this app, since it allows me to use the upn System of my hp35s which is much better in the long term… I don’t find anything bad about the app, so it’s the 5 Stars :)

Just exactly the calculator app I needed. Thank you..

I loved my 42S - now I love this App! Thanks for the good work!

Really cool app. Works like a charm.

So nice to have this available. I have always been a diehard HP RPN calculator fan. This app is a faithful and convenient reproduction.

Not sure why, but the square root function doesn’t seem to be working properly now. Was working okay before. Not sure if other functions are also impacted. Used to love this up until this happened

I have always used HP RPN calculators spanning a period of over fifty years and this App is a faultless rendition of the original calculator. One really niggling problem is that the screen has rotated 90 degrees to landscape. Trying to get it back to portrate does not work. Any ideas? Any fix coming? Ray Shead

I’ve been using my hp42 since buying it the day it was in stock for sale. Its a one-owner! On back it says 1987 Made in USA. SERIAL No …A11141. I digress. Some of my keys have started to act up after 36 years of perfect service. Finding Free42 is a godsend! I’m running it on an iPhone SE. I re-entered some really old programs I’ve kept on my 42s and they work flawlessly. I am so grateful you’ve created this app. Thank you, thank you!

I’ve been a fan of RPN for over 40 years. This calculator works great. I don’t typically use it for much more than simple calculations but I use it daily. I absolutely love the haptic feedback with key presses. It’s gives great indication when you’ve typed a number.