# DeepFocus Study vs Sajeon

The clearest difference is in-app purchases: DeepFocus Study at none against Sajeon's 3. DeepFocus Study also leads on iOS requirement (15.0 vs 26.0). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Sajeon sells 3 in-app purchases, starting at $2.99 per month. DeepFocus Study asks for nothing beyond the download.

DeepFocus Study ships an update weekly, Sajeon every 6 days. The most recent releases landed on November 9, 2026 and November 13, 2026 respectively.

## The numbers

| Metric | DeepFocus Study | Sajeon |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Weekly | **Every 6 days** |
| Monetization | — | Freemium |
| Size | 6 MB | 286 MB |
| Requires iOS | **15.0** | 26.0 |
| Devices | iPhone, iPod | **iPhone, iPad, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Vladyslav Lavreniuk](https://appshunter.io/developer/1885541469) | [Dittman Shum](https://appshunter.io/developer/1492526802) |

## What reviewers say

### DeepFocus Study

[App page](https://appshunter.io/ios/app/deepfocus-study/id6760655791)

**Features:** macOS Compatibility

**In-app purchases:** none


### Sajeon

[App page](https://appshunter.io/ios/app/sajeon-korean-dictionary/id6761698356)

Master Korean with a comprehensive dictionary featuring over 50,000 entries. Analyze text with a clipboard reader, practice pronunciation with text-to-speech, and enhance learning with custom word lists and categorized references. Unlock advanced features like conjugations and OCR scanning with a premium subscription.

**Highlights:** Extensive Korean dictionary with 50,000+ entries, Clipboard text analysis and word identification, Customizable word lists for revision, Native-quality text-to-speech for pronunciation, Advanced verb/adjective conjugations, Spaced Repetition System (SRS) flashcards, Instant OCR camera scanning for real-world text

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Sajeon Premium Monthly | $2.99 | per month |
| Sajeon Premium Yearly | $14.99 | per year |
| Sajeon Premium Lifetime | $49.99 | one-time |


## Frequently asked questions

### Is DeepFocus Study free?

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

### Is Sajeon free?

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

### Do DeepFocus Study or Sajeon have ads?

Neither DeepFocus Study nor Sajeon shows ads.

### Which is updated more often, DeepFocus Study or Sajeon?

DeepFocus Study ships an update weekly, and Sajeon every 6 days. Most recently, DeepFocus Study was updated on November 9, 2026 and Sajeon on November 13, 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.*