# N'Back Butterfly vs Mono

The clearest difference is update cadence: Mono at every 4 days against N'Back Butterfly's every 10 months. Mono also leads on iOS requirement (13.4 vs 15.6). On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

N'Back Butterfly ships an update every 10 months, Mono every 4 days. The most recent releases landed on November 1, 2026 and November 4, 2026 respectively.

## The numbers

| Metric | N'Back Butterfly | Mono |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/mono-puzzles/id6475032746/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | Yes | Yes |
| Update frequency | Every 10 months | **Every 4 days** |
| Monetization | Ad-supported | Ad-supported |
| Size | 9 MB | 32 MB |
| Requires iOS | 15.6 | **13.4** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Yasuyoshi Ota](https://appshunter.io/developer/1500357652) | [Tomohiro Ichiba](https://appshunter.io/developer/1686104527) |

## What reviewers say

### N'Back Butterfly

[App page](https://appshunter.io/ios/app/nback-butterfly/id853507894)

Enhance your cognitive abilities and combat forgetfulness with this application designed to improve working memory. It utilizes the scientifically recognized n-back task to train your brain's capacity for information recall and manipulation.

**Highlights:** Working memory improvement, N-back task training, Cognitive neuroscience assessment, Continuous performance task

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

**In-app purchases:** none


### Mono

[App page](https://appshunter.io/ios/app/mono-puzzles/id6475032746)

A minimalist puzzle game where players aim to reduce the number of stones on a board to a single one. Stones can jump over adjacent stones, removing the jumped stone. This strategic elimination continues until only one stone remains.

**Highlights:** Single stone objective, Jump over stones to eliminate, Vertical and horizontal jumps, Minimalist design, Brain-training gameplay

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is N'Back Butterfly free?

N'Back Butterfly is free to download, with no in-app purchases.

### Is Mono free?

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

### Do N'Back Butterfly or Mono have ads?

Both N'Back Butterfly and Mono show ads.

### Which is updated more often, N'Back Butterfly or Mono?

N'Back Butterfly ships an update every 10 months, and Mono every 4 days. Most recently, N'Back Butterfly was updated on November 1, 2026 and Mono 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.*