# AI Study Sheet vs 문득

The clearest difference is review sentiment: AI Study Sheet at 100% against 문득's 43%. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. AI Study Sheet sells 1 one-off in-app purchase and 문득 sells 2 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

Both ship on a similar rhythm, roughly every 3 days. The most recent releases landed on October 15, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | AI Study Sheet | 문득 |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | **100.0% of reviews** | 42.9% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 days | Every 3 days |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 8 MB | 37 MB |
| Requires iOS | **16.0** | 17.2 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 12+ |
| Developer | [Masaki Iino](https://appshunter.io/developer/6778272211) | [JIHWAN YEOM](https://appshunter.io/developer/6805761199) |

## What reviewers say

### AI Study Sheet

[App page](https://appshunter.io/ios/app/ai-study-sheet-active-recall/id6782023263)

Transform existing study materials into active-recall quizzes with AI. Snap photos or import PDFs, and the app automatically masks key terms for spaced repetition. Review materials with an auto-reveal mode that adapts to your learning behavior.

**Highlights:** Import photos and PDFs, Automatic AI masking of key terms, Review reminders, Auto Study Mode with sequential reveal, Adaptive learning based on study behavior, Organized study material library, Flexible material viewing and editing

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlimited Saves | $4.99 | one-time |


### 문득

[App page](https://appshunter.io/ios/app/ai-pdf/id6805761197)

This app generates AI-powered quizzes from your PDF, PPT, or Notion notes. Review material directly on your phone's lock screen, with spaced repetition for optimal recall. It automatically creates questions, answers, and options, saving you time on flashcard creation.

**Highlights:** AI quiz generation from PDF, PPT, Notion, Lock screen review cards, Spaced repetition for optimal recall, Automatic question, answer, and option creation, Mock exam mode, Customizable review intervals

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 문득 베이직 | $1.99 | per month |
| 크레딧 10개 | $1.99 | one-time |


## Frequently asked questions

### Is AI Study Sheet free?

AI Study Sheet is free to download, with in-app purchases available.

### Is 문득 free?

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

### Do AI Study Sheet or 문득 have ads?

Neither AI Study Sheet nor 문득 shows ads.

### Which is updated more often, AI Study Sheet or 문득?

AI Study Sheet ships an update every 3 days, and 문득 every 3 days. Most recently, AI Study Sheet was updated on October 15, 2026 and 문득 on October 9, 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.*