# RPN Calc vs 3D Stress

The clearest difference is update cadence: 3D Stress at every 2 weeks against RPN Calc's every 3 months. RPN Calc's advantage is price ($0.99 vs $2.99). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

RPN Calc costs $0.99 and 3D Stress $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

RPN Calc ships an update every 3 months, 3D Stress every 2 weeks. The most recent releases landed on November 10, 2026 and November 4, 2026 respectively.

## The numbers

| Metric | RPN Calc | 3D Stress |
| --- | --- | --- |
| Price | **$0.99** | $2.99 |
| Rating | **[4.0 (6 ratings)](https://appshunter.io/ios/app/rpn-calc/id285002799/reviews)** | — |
| Number of ratings | **6** | — |
| Positive reviews | 34.3% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 2 weeks** |
| Monetization | Free | — |
| Size | 3 MB | 4 MB |
| Requires iOS | 16.0 | **15.0** |
| Devices | iPhone, iPad, Apple Watch | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [James Mattis](https://appshunter.io/developer/285002802) | [Konstantinos Ladiellis](https://appshunter.io/developer/1516103440) |

## What reviewers say

### RPN Calc

[App page](https://appshunter.io/ios/app/rpn-calc/id285002799)

This app provides a straightforward reverse Polish notation (RPN) calculator experience, inspired by classic HP models. It offers a clean interface with large buttons for quick calculations on iPhone, iPad, and Apple Watch, along with a convenient Today Extension for immediate access.

**Highlights:** Reverse Polish Notation (RPN) input, Clean, simple interface, Large, easy-to-press buttons, iPhone, iPad, and Apple Watch support, Today Extension for quick access

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support, iPhone Duo support

**In-app purchases:** none


### 3D Stress

[App page](https://appshunter.io/ios/app/3d-stress/id6503481793)

**In-app purchases:** none


## Frequently asked questions

### Is RPN Calc free?

RPN Calc costs $0.99, with no in-app purchases.

### Is 3D Stress free?

3D Stress costs $2.99, with no in-app purchases.

### Do RPN Calc or 3D Stress have ads?

Neither RPN Calc nor 3D Stress shows ads.

### Which is updated more often, RPN Calc or 3D Stress?

RPN Calc ships an update every 3 months, and 3D Stress every 2 weeks. Most recently, RPN Calc was updated on November 10, 2026 and 3D Stress on November 4, 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.*