# PolyFill vs MentalMather

The clearest difference is rating: MentalMather at 5.0 against PolyFill's 2.3. MentalMather also leads on in-app purchases (none vs 3) and update cadence (every 3 weeks vs every 6 months). On price, ratings volume, ads and device support there is nothing between them.

Both are free to download. PolyFill sells 3 one-off in-app purchases. MentalMather asks for nothing beyond the download.

MentalMather holds the better App Store score, 5.0 against 2.3. Both are backed by a comparable volume of ratings — 3 and 2 respectively.

PolyFill ships an update every 6 months, MentalMather every 3 weeks. The most recent releases landed on October 23, 2026 and October 21, 2026 respectively.

## The numbers

| Metric | PolyFill | MentalMather |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.3 (3 ratings)](https://appshunter.io/ios/app/polyfill/id987147033/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/mentalmather/id6760533092/reviews)** |
| Number of ratings | **3** | 2 |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | Yes | Yes |
| Update frequency | Every 6 months | **Every 3 weeks** |
| Monetization | Free with in-app purchases | **Ad-supported** |
| Size | 15 MB | 55 MB |
| Requires iOS | **14.0** | 15.5 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 12+ |
| Developer | [Kelly Technology Inc.](https://appshunter.io/developer/393931941) | [Cortex Apps llc](https://appshunter.io/developer/1884834782) |

## What reviewers say

### PolyFill

[App page](https://appshunter.io/ios/app/polyfill/id987147033)

A brain-training puzzle game where you race against the clock to assemble geometric shapes. Earn points based on difficulty and speed, and compete on leaderboards. Unlock additional complexity and scoring through optional in-app purchases.

**Highlights:** Brain-training puzzles, Timed challenges, Geometric shape assembly, Scoring based on difficulty and time, Game Center leaderboards, Achievement awards, In-app purchases for complexity

**Features:** Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove ads. | $1.99 | one-time |
| Unlock level 2 | $1.99 | one-time |
| Unlock level 3 | $1.99 | one-time |


### MentalMather

[App page](https://appshunter.io/ios/app/mentalmather/id6760533092)

Track your daily cognitive sharpness with mental math exercises. This app measures your brain's current performance against your personal baseline, not to teach math but to gauge your mental acuity.

**Highlights:** Daily Sharpness Score, Personalized baseline comparison, Guided and Quick Play modes, Shareable challenges with friends, Detailed session history and analytics, Offline functionality

**In-app purchases:** none


## Frequently asked questions

### Is PolyFill free?

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

### Is MentalMather free?

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

### Which has better reviews, PolyFill or MentalMather?

MentalMather is rated higher. PolyFill averages 2.3 out of 5 from 3 ratings, while MentalMather averages 5.0 from 2 ratings.

### Do PolyFill or MentalMather have ads?

Both PolyFill and MentalMather show ads.

### Which is updated more often, PolyFill or MentalMather?

PolyFill ships an update every 6 months, and MentalMather every 3 weeks. Most recently, PolyFill was updated on October 23, 2026 and MentalMather on October 21, 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.*