# NumMemorize vs Collatz Explorer

The clearest difference is rating: NumMemorize at 5.0 against Collatz Explorer's 4.6. NumMemorize also leads on device support (3 vs 1) and iOS requirement (9.0 vs 18.6). Collatz Explorer's advantage is update cadence (monthly vs every 4 months) and ratings volume (7 vs 1). On price, review sentiment, ads and in-app purchases there is nothing between them.

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

NumMemorize holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: Collatz Explorer has 7 ratings behind it against 1, so its average is the more settled of the two. Written reviews split almost evenly too, at 100% and 100% positive.

NumMemorize ships an update every 4 months, Collatz Explorer monthly. The most recent releases landed on September 28, 2026 and September 27, 2026 respectively.

## The numbers

| Metric | NumMemorize | Collatz Explorer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/nummemorize/id310151986/reviews)** | [4.6 (7 ratings)](https://appshunter.io/ios/app/collatz-explorer/id6755121221/reviews) |
| Number of ratings | 1 | **7** |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Monthly** |
| Monetization | Free | Free |
| Size | 3 MB | 1 MB |
| Requires iOS | **9.0** | 18.6 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Mahboud Zabetian](https://appshunter.io/developer/310151989) | [Berk Sucu](https://appshunter.io/developer/1852063488) |

## What reviewers say

### NumMemorize

[App page](https://appshunter.io/ios/app/nummemorize/id310151986)

This app helps users memorize digits of mathematical constants like pi and e through quizzes. It also allows users to input and memorize their own custom numbers, and offers voice input for convenience.

**Highlights:** Memorize digits of pi, e, and other constants, Quiz yourself on number recall, Input and memorize custom numbers, Voice input for number entry, Practice for math and science students

**Features:** macOS Compatibility

**In-app purchases:** none


### Collatz Explorer

[App page](https://appshunter.io/ios/app/collatz-explorer/id6755121221)

Explore mathematical sequences with this app. It calculates the standard Collatz sequence for any number you enter and can also display sequences from an alternative 3x-1 function.

**Highlights:** Calculate Collatz sequences, Calculate 3x-1 function sequences, Input any number, Visualize sequences

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

**In-app purchases:** none


## Frequently asked questions

### Is NumMemorize free?

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

### Is Collatz Explorer free?

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

### Which has better reviews, NumMemorize or Collatz Explorer?

NumMemorize is rated higher. NumMemorize averages 5.0 out of 5 from 1 ratings, while Collatz Explorer averages 4.6 from 7 ratings.

### Do NumMemorize or Collatz Explorer have ads?

Neither NumMemorize nor Collatz Explorer shows ads.

### Which is updated more often, NumMemorize or Collatz Explorer?

NumMemorize ships an update every 4 months, and Collatz Explorer monthly. Most recently, NumMemorize was updated on September 28, 2026 and Collatz Explorer on September 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.*