RPN 30

It’s the best simple RPN calculator in App Store. If you’re an addicted old scholar HP user, that’s the App!

I’ve been using a physical 42S and emulator on my phone for years. The down side is that the keys and display font are small. Apple default calculator app, on the other hand, have very large font and large key size, but it’s not RPN. This calculator here has the potential to be a great alternative to both, but it’s not (yet). 1. Stack display is a bit confusing. Took me a while to figure out Y is on top left corner, and then the next 3 levels up on the right. It would be more consistent if you skip the top left corner position, and just have the stack on the right. 2. While alternate functions are activated by long pressing the number keys/layer, in the advanced function keys/layer, it requires pressing ALT then another key. Why the different behavior? 3. Store/recall does not work at all.

I agree with Talasoft guy. I went through engineering school using an HP 15 C calculator. I found this calculator too confusing to use. The developer might want to consider that people looking for an RPN calculator app are those of us who are familiar with RPN and don’t want to carry around a calculator anymore. In other words don’t alienate the people who are most likely to use your app. Furthermore, I am not sure anyone trying to learn RPN will make any sense to what’s happening on this calculator.

Nice and simple RPN calculator. If the font size of the stack numbers were bigger, it would be perfect.

Couldn’t ask for a better RPN calculator for iOS

The rpn app I had been using for years is no longer available, so I switched to this one. I’m glad I did; it’s very good. I had a question about using it and emailed the developer; he got right back to me with the information I needed. If you use reverse Polish notation, give this a try.

Does what it needs, doesn't beg you for money, stays out of your way and lets you calculate. Thank you so much!

RPN30 is a fantastic implementation of RPN in an easy to understand and use calculator. The HP calculator emulators are good but can be too complex and have unneeded features for 90% of people's need. This will be my go-to everyday calculator.

I have been using hp calculators with rpn notation since the 80s. With the addition of the rectangular to polar and polar to rectangular conversion feature added to this app. I really have no need for an actual physical calculator any more. Thanks a bunch

This is a great simple (and robust) rpn calculator. The navigation is smart, but not very intuitive. Needs more extensive, or easier to find, instructions.