# RPN vs Refuel Buddy

The clearest difference is update cadence: RPN at every 2 months against Refuel Buddy's every 22 months. RPN also leads on iOS requirement (12.0 vs 15.1). Refuel Buddy's advantage is price ($1.99 vs $2.99). On ads, in-app purchases and device support there is nothing between them.

RPN costs $2.99 and Refuel Buddy $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

RPN ships an update every 2 months, Refuel Buddy every 22 months. The most recent releases landed on November 3, 2026 and November 8, 2026 respectively.

## The numbers

| Metric | RPN | Refuel Buddy |
| --- | --- | --- |
| Price | $2.99 | **$1.99** |
| Rating | **[4.3 (10 ratings)](https://appshunter.io/ios/app/rpn-25-ce/id1529311398/reviews)** | — |
| Number of ratings | **10** | — |
| Positive reviews | 80.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 22 months |
| Monetization | Paid | — |
| Size | 28 MB | 6 MB |
| Requires iOS | **12.0** | 15.1 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 17+ |
| Developer | [CuVee Software](https://appshunter.io/developer/424873503) | [htin kyaw](https://appshunter.io/developer/1727112077) |

## What reviewers say

### RPN

[App page](https://appshunter.io/ios/app/rpn-25-ce/id1529311398)

This app is a photo-realistic simulation of the classic HP-25 scientific calculator. It offers advanced programming features, a vast function library, and modern enhancements for enhanced usability on iOS devices.

**Highlights:** Photo-realistic simulation, Programmable (99/999 steps), 15 user-defined function keys, 100 symbolic labels, 100 visible registers, Program library with 150+ programs, Over 270 functions

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### Refuel Buddy

[App page](https://appshunter.io/ios/app/refuel-buddy/id6477700959)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is RPN free?

RPN costs $2.99, with no in-app purchases.

### Is Refuel Buddy free?

Refuel Buddy costs $1.99, with no in-app purchases.

### Do RPN or Refuel Buddy have ads?

Neither RPN nor Refuel Buddy shows ads.

### Which is updated more often, RPN or Refuel Buddy?

RPN ships an update every 2 months, and Refuel Buddy every 22 months. Most recently, RPN was updated on November 3, 2026 and Refuel Buddy on November 8, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*