# ClassSync vs Thinkbig TOPIK

The clearest difference is in-app purchases: ClassSync at none against Thinkbig TOPIK's 5. Thinkbig TOPIK's advantage is update cadence (every 2 weeks vs every 9 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Thinkbig TOPIK sells 5 in-app purchases, starting at $9.99 per month. ClassSync asks for nothing beyond the download.

ClassSync ships an update every 9 months, Thinkbig TOPIK every 2 weeks. The most recent releases landed on September 18, 2026 and September 28, 2026 respectively.

## The numbers

| Metric | ClassSync | Thinkbig TOPIK |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | — | 87.5% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 9 months | **Every 2 weeks** |
| Monetization | — | Free with in-app purchases |
| Size | 30 MB | 30 MB |
| Requires iOS | 13.0 | **12.4** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 17+ |
| Developer | [Classsync Technology](https://appshunter.io/developer/1750642602) | [Woongjin Thinkbig Co., Ltd.](https://appshunter.io/developer/1614968450) |

## What reviewers say

### ClassSync

[App page](https://appshunter.io/ios/app/classsync/id6504002003)

**Features:** macOS Compatibility

**In-app purchases:** none


### Thinkbig TOPIK

[App page](https://appshunter.io/ios/app/thinkbig-topik/id6736814780)

Enhance your TOPIK score with AI-powered, customized learning. This app offers structured courses, practice questions, and mock tests tailored to your skill level. Track your progress and review difficult concepts to prepare effectively for the exam.

**Highlights:** AI-based customized learning curriculum, 12 courses for TOPIK levels 1-6, Practice questions and mock tests, Vocabulary and grammar review, Writing exercises with feedback, Progress tracking and real-time evaluation, Multi-language support

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 1-Month Plan Trial | $9.99 | per month |
| 1-Month Plan | $9.99 | per month |
| 3-Month Plan | $44.99 | one-time |
| 6-Month Plan | $77.99 | one-time |
| 12-Month Plan | $118.99 | one-time |


## Frequently asked questions

### Is ClassSync free?

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

### Is Thinkbig TOPIK free?

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

### Do ClassSync or Thinkbig TOPIK have ads?

Neither ClassSync nor Thinkbig TOPIK shows ads.

### Which is updated more often, ClassSync or Thinkbig TOPIK?

ClassSync ships an update every 9 months, and Thinkbig TOPIK every 2 weeks. Most recently, ClassSync was updated on September 18, 2026 and Thinkbig TOPIK on September 28, 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.*