# PrefixCalc vs Twin Calc

The clearest difference is in-app purchases: PrefixCalc at none against Twin Calc's 1. PrefixCalc also leads on device support (3 vs 1) and iOS requirement (12.0 vs 16.4). On price and ads there is nothing between them.

Both are free to download. Twin Calc sells 1 one-off in-app purchase. PrefixCalc asks for nothing beyond the download.

## The numbers

| Metric | PrefixCalc | Twin Calc |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Size | 28 MB | 45 MB |
| Requires iOS | **12.0** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [YONAGARE LAB](https://appshunter.io/developer/1810986554) | [Hiroki Sugiyama](https://appshunter.io/developer/6778858327) |

## What reviewers say

### PrefixCalc

[App page](https://appshunter.io/ios/app/prefixcalc/id6748650037)

**Features:** macOS Compatibility

**In-app purchases:** none


### Twin Calc

[App page](https://appshunter.io/ios/app/twin-calc-two-calculators/id6807615879)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PRO | $3.99 | one-time |


## Frequently asked questions

### Is PrefixCalc free?

PrefixCalc is free to download, with no in-app purchases.

### Is Twin Calc free?

Twin Calc is free to download, with in-app purchases available.

### Do PrefixCalc or Twin Calc have ads?

Neither PrefixCalc nor Twin Calc shows ads.

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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.*