# Modulo Calculator. vs Dual

The clearest difference is price: Modulo Calculator. at Free against Dual's $0.99. Modulo Calculator. also leads on iOS requirement (12.0 vs 16.6). Dual's advantage is ads (none vs shown) and update cadence (every 2 days vs every 4 months). On in-app purchases and device support there is nothing between them.

Modulo Calculator. is free to download; Dual costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Modulo Calculator. ships an update every 4 months, Dual every 2 days. The most recent releases landed on October 9, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | Modulo Calculator. | Dual |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | — | **[4.8 (4 ratings)](https://appshunter.io/ios/app/dual-n-back/id6744232772/reviews)** |
| Number of ratings | — | **4** |
| Positive reviews | — | 90.0% of reviews |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Every 4 months | **Every 2 days** |
| Monetization | — | Paid |
| Size | 29 MB | 1 MB |
| Requires iOS | **12.0** | 16.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Milos Lukas Ziolkowski](https://appshunter.io/developer/1778486821) | [Andrew Tang](https://appshunter.io/developer/1806563018) |

## What reviewers say

### Modulo Calculator.

[App page](https://appshunter.io/ios/app/modulo-calculator/id6737914141)

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

**In-app purchases:** none


### Dual

[App page](https://appshunter.io/ios/app/dual-n-back/id6744232772)

This cognitive training game is designed to enhance working memory through a simple yet challenging experience. It offers a clean interface with detailed history tracking and customizable gameplay and aesthetics. All data is stored locally for enhanced privacy.

**Highlights:** Working memory improvement, Detailed game history, Replay previous rounds, Gameplay customization, Aesthetic customization, Local data storage

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

**In-app purchases:** none


## Frequently asked questions

### Is Modulo Calculator. free?

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

### Is Dual free?

Dual costs $0.99, with no in-app purchases.

### Do Modulo Calculator. or Dual have ads?

Modulo Calculator. shows ads; Dual does not.

### Which is updated more often, Modulo Calculator. or Dual?

Modulo Calculator. ships an update every 4 months, and Dual every 2 days. Most recently, Modulo Calculator. was updated on October 9, 2026 and Dual on October 7, 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.*