# RPN Anywhere — user reviews

> 18 indexed App Store user reviews of RPN Anywhere by Hiroki Kawakami, rated 4.46/5 from 28 ratings.

- Source: https://appshunter.io/ios/app/rpn-anywhere/id1250545319/reviews
- App overview in markdown: https://appshunter.io/ios/app/rpn-anywhere/id1250545319.md
- Rating breakdown: 5★ 18 · 4★ 7 · 3★ 2 · 2★ 0 · 1★ 1

## Most critical reviews (10 lowest-rated)

### 1/5 — A waste of time and money

*2022-03-22*

Copy, paste are broken.  No instructions or many. 

Unbelievably bad app.

### 2/5 — やくだたない

*2022-03-01, version 5.1*

カッコが使えない，つまらない。

### 3/5 — Functional, but UX desperately needs work on WatchOS

*2024-11-07*

Functionally, this is a pretty competent RPN calculator. The design isn't trying to directly copy an old HP interface and it's the better for it. On iOS, that's essentially the end of the story. It works.
On WatchOS, the user interface design has a number of major inconsistencies with standard UI patterns:

The watch app is organized as a single screen with two trays at the top and bottom. The trays are accessed exclusively via touch. The stack is in the top tray and advanced functions are in the bottom tray. This is quite different from most software for the Watch, which generally use sliding cards to access things which don't fit on one screen.

The lower tray, sensibly enough, is accessed by swiping upwards anywhere on the bottom edge of the display and dismissed by swiping downwards.

The upper tray, on the other hand, is accessed by swiping down from the right half of the top edge of the display. There does not appear to be any function assigned to the left half of the display. The tray is dismissed by swiping upwards, but a full row of space in the stack is dedicated to a large "back" button which duplicates this for no discernible reason.

This arrangement simply isn't very good. Every Watch includes a hardware control for vertical movement and it's not used in any way despite the use of vertical movement for navigation. The touch controls are implemented strangely. The end result feels very non-native, is fiddly to use, and generally lacks polish.

### 3/5 — bug report - apple watch:

*2020-07-15*

Arc tan does not appear to work.  Need this fixed asap.  Trig functions are the only reason I purchased this app.

### 3/5 — 1e-5より小さい数

*2019-10-25, version 3.1*

例えば、0.000001を入力すると、NaNe-6と表示されて計算できないようです。

### 4/5 — Almost perfect

*2025-07-31*

This is by far the best Apple Watch calculator app, period. 
Unfortunately there seems to be a bug where the programs you create on the iPhone do not sync to the watch. 
Even with this bug, this is still well worth buying over the Lite version of this app.

### 4/5 — Great app if you prefer R.P.N. But…

*2023-01-06*

Have been using this app for several years and it is my go to calculator.  But one thing is missing. Can you please add a number storage for number recall?  Like a memory 1 and Memory 2 button.  The stack is great not often I want to perform several different operations on the same number.

### 4/5 — Bugs

*2022-09-17*

Copy accumulator (X) doesn’t seem to work. V5.1, Ios 15.5, iPhone 8 Copy All doesn’t seem to work Cut will delete, but doesn’t put the number on the clipboard Paste doesn’t seem to work

### 4/5 — Great RPN Calculator!

*2022-06-10*

If you're looking for a simple RPN calc that features keyboard input that makes sense (and/of is customizable) compared to the default calculator (in RPN mode) then get this calc.
The only things I wish it had are a few more GUI keys. An EE key in "basic" mode would be nice, and more stack control keys (Roll up/down, Drop) in both modes for when you want to be lazy and only use the mouse. The "scientific" mode already features an EE key and thanks to the programming function I added the stack control keys as programs. Programs appear as keys below the display starting at the left, I added a couple blank programs with spaces for titles to move my stack control keys above the numeric keys. It's almost perfect!

### 4/5 — バイブレーションについて

*2019-07-27, version 3.0*

RPNの簡易に使えるのを探していたので、満足しています。
ただボタンのバイブレーションですが、ボタンを離す時ではなく、押した時に動作してもらうと助かります。

## Most praised reviews (8 highest-rated)

### 5/5 — 小学生でも使えるRPN計算機

*2025-10-20, version 5.1*

大変使いやすいRPN計算機で、小学生の子供も、１度使ったら、この計算機以外は使いたがらないようです。
やり方がわかっていないのかもですが、iPhone, iPadで使用しているときに、スワイプ入力などで、”一つ前の計算に戻る・取り消し”処理が行えないのが残念です。

### 5/5 — RPN計算機の中で一番のおすすめ

*2025-10-03, version 5.1*

表示がシンプルで見やすいです。RPN操作に必要最小限のボタンが用意されていて、使いやすいです。それでいて「科学計算」モードに切り替えると、多数の関数が使えるようになります。さらには、プログラミング電卓の機能もあります。RPN計算機アプリは多数試しましたが、これが一番良いです。「カッコが使えない」という他の方の評価がありますが、RPN計算機に対してそれは褒め言葉だと思います。

### 5/5 — Great calculator!

*2024-11-02*

This is a great RPN calculator. I use it regularly on my Mac. 
Please update the Mac app so that it saves the *size* of the window. I have to make it larger every time I open the app.

### 5/5 — Visualising the stack

*2024-09-24*

How can we do it?

### 5/5 — The best

*2024-05-30*

The best!!!

### 5/5 — Best practical programmable RPN iOS calculator

*2020-11-07*

Though I am eager to give this app 5 stars, I bought this for use on my Series5 watch but find that there is a bug with WatchOS 7.1 which won't let me swipe to get back to main from the function screens. Unfortunately, the app support page is not in English, so I don't know if there's a workaround.

So why did I give it 4 stars even though it has a debilitating bug?  It is unapologetically RPN. The layout and functionality isn't perfect; but it is the most practical design I have seen for writing useful scientific/engineering programs on an iOS device. The layout and functionality on an iPad is stellar.

I will definitely keep this app hoping that the watch bug gets fixed. It is very much worth it's price.

### 5/5 — Bug report

*2019-02-05*

App reports 3.17^(1/36)=4.89e163. 
Correct answer is ~1.0326.  
This error occurs for all 3 page #1 functions:
X^y, Y^x or Yth root X.
Occurs on iPhone and watch. 
Interestingly 30.91^(1/36)=1.1 correct!

One quirk: Swipe up brings up the extensive operators pages with buttons to select between #1, #2 or PRGM but then you are stuck there... until you notice that only a “short” down swipe and not from top of screen, but center or bottom third gets you back to the main screen. 

This is my first really useful calculator for the Apple Watch!

**Developer response:** I apologize for the bug.

In this app, x^y is calculated as e^(y * ln x) and I found a bug in e^x.
I forgot to check underflow while calculating power series of exponential formula.
Therefore, the bug is appear when x is small and calculate e^x.

I fixed that bug in version 2.5 .
So please update to fix it.

### 5/5 — Full featured app

*2018-09-17*

It takes some practice but it works well once you get used to it

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-10.*