# Grade 9 Math Mastery vs Skim

The clearest difference is update cadence: Skim at every 2 weeks against Grade 9 Math Mastery's every 5 months. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Grade 9 Math Mastery sells 2 in-app purchases, starting at $4.99 per month and Skim sells 4 in-app purchases, starting at $6.99 per month. Whichever you choose, the download price is not the number that matters.

Grade 9 Math Mastery ships an update every 5 months, Skim every 2 weeks. The most recent releases landed on October 15, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | Grade 9 Math Mastery | Skim |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (3 ratings)](https://appshunter.io/ios/app/skim-micro-learning-cards/id6764439998/reviews)** |
| Number of ratings | — | **3** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 2 weeks** |
| Monetization | — | Freemium |
| Size | 7 MB | 10 MB |
| Requires iOS | 17.0 | 17.0 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Eager.app](https://appshunter.io/developer/1550371160) | [DORUK SAVASAN](https://appshunter.io/developer/1895781498) |

## What reviewers say

### Grade 9 Math Mastery

[App page](https://appshunter.io/ios/app/grade-9-math-mastery/id6760619466)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Grade 9 Math Mastery — Monthly | $4.99 | per month |
| Grade 9 Math Mastery — Annual | $29.99 | per year |


### Skim

[App page](https://appshunter.io/ios/app/skim-micro-learning-cards/id6764439998)

Transform documents into bite-sized learning cards with AI. Choose from four learning modes, ask questions about terms, and track your progress. Ideal for students, researchers, and professionals.

**Highlights:** AI-generated learning cards, Multiple learning modes (Deep Understanding, ELI5, Memorize, Quick Review), Ask AI questions about document terms, Progress tracking (streak, mastery, accuracy), Supports PDF, Word, PowerPoint, text, and Markdown, No ads or data tracking

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Monthly | $6.99 | per month |
| Ultra Monthly | $13.99 | per month |
| Pro Annual | $69.99 | per year |
| Ultra Annual | $139.99 | per year |


## Frequently asked questions

### Is Grade 9 Math Mastery free?

Grade 9 Math Mastery is free to download, with in-app purchases available.

### Is Skim free?

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

### Do Grade 9 Math Mastery or Skim have ads?

Neither Grade 9 Math Mastery nor Skim shows ads.

### Which is updated more often, Grade 9 Math Mastery or Skim?

Grade 9 Math Mastery ships an update every 5 months, and Skim every 2 weeks. Most recently, Grade 9 Math Mastery was updated on October 15, 2026 and Skim 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.*