# A3Calc vs RST Scope Pro

The clearest difference is update cadence: RST Scope Pro at every 6 days against A3Calc's every 18 months. A3Calc's advantage is iOS requirement (12.0 vs 15.6). On price, ads, in-app purchases and device support there is nothing between them.

A3Calc costs $1.99 and RST Scope Pro $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

A3Calc ships an update every 18 months, RST Scope Pro every 6 days. The most recent releases landed on October 26, 2026 and October 27, 2026 respectively.

## The numbers

| Metric | A3Calc | RST Scope Pro |
| --- | --- | --- |
| Price | $1.99 | $1.99 |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 18 months | **Every 6 days** |
| Size | 2 MB | 1 MB |
| Requires iOS | **12.0** | 15.6 |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Farren Domenici](https://appshunter.io/developer/583666476) | [koji kamogawa](https://appshunter.io/developer/1488210713) |

## What reviewers say

### A3Calc

[App page](https://appshunter.io/ios/app/a3calc/id1340952531)

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

**In-app purchases:** none


### RST Scope Pro

[App page](https://appshunter.io/ios/app/rst-scope-pro/id1550939327)

**In-app purchases:** none


## Frequently asked questions

### Is A3Calc free?

A3Calc costs $1.99, with no in-app purchases.

### Is RST Scope Pro free?

RST Scope Pro costs $1.99, with no in-app purchases.

### Do A3Calc or RST Scope Pro have ads?

Neither A3Calc nor RST Scope Pro shows ads.

### Which is updated more often, A3Calc or RST Scope Pro?

A3Calc ships an update every 18 months, and RST Scope Pro every 6 days. Most recently, A3Calc was updated on October 26, 2026 and RST Scope Pro on October 27, 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.*