# Therefore vs Chengyu Calendar

The clearest difference is in-app purchases: Therefore at none against Chengyu Calendar's 3. Therefore also leads on device support (3 vs 1) and iOS requirement (15.1 vs 18.0). On price, update cadence and ads there is nothing between them.

Both are free to download. Chengyu Calendar sells 3 in-app purchases, starting at $0.99 per 7 days. Therefore asks for nothing beyond the download.

Therefore ships an update every 3 days, Chengyu Calendar every 2 days. The most recent releases landed on October 4, 2026 and October 19, 2026 respectively.

## The numbers

| Metric | Therefore | Chengyu Calendar |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[3.9 (7 ratings)](https://appshunter.io/ios/app/chengyu-calendar/id6813331921/reviews)** |
| Number of ratings | — | **7** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 days | **Every 2 days** |
| Monetization | — | Subscription |
| Size | 27 MB | 107 MB |
| Requires iOS | **15.1** | 18.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 12+ | 4+ |
| Developer | [Michael Stanfield](https://appshunter.io/developer/1018192064) | [Fiachra MacFadden](https://appshunter.io/developer/1831200997) |

## What reviewers say

### Therefore

[App page](https://appshunter.io/ios/app/therefore/id6757112275)

**Features:** macOS Compatibility

**In-app purchases:** none


### Chengyu Calendar

[App page](https://appshunter.io/ios/app/chengyu-calendar/id6813331921)

Learn a new Chinese idiom daily with a widget that mimics a traditional tear-off calendar. Explore idiom history, meanings, and usage examples. Supports both Simplified and Traditional Chinese characters and works offline without ads.

**Highlights:** Daily idiom widget, Idiom breakdown (character, pinyin, meaning), Example sentences, Idiom history and origin, Simplified/Traditional character support, Offline functionality, Ad-free and private

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly | $0.99 | per 7 days |
| Monthly | $2.99 | per month |
| Yearly | $24.99 | per year |


## Frequently asked questions

### Is Therefore free?

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

### Is Chengyu Calendar free?

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

### Do Therefore or Chengyu Calendar have ads?

Neither Therefore nor Chengyu Calendar shows ads.

### Which is updated more often, Therefore or Chengyu Calendar?

Therefore ships an update every 3 days, and Chengyu Calendar every 2 days. Most recently, Therefore was updated on October 4, 2026 and Chengyu Calendar on October 19, 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.*