# Contextionary App vs AI错题树

The clearest difference is update cadence: Contextionary App at every 2 days against AI错题树's every 10 days. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Contextionary App sells 2 in-app purchases, starting at $4.99 per month and AI错题树 sells 3 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

Contextionary App ships an update every 2 days, AI错题树 every 10 days. The most recent releases landed on September 10, 2026 and September 21, 2026 respectively.

## The numbers

| Metric | Contextionary App | AI错题树 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/ai/id6771737023/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 2 days** | Every 10 days |
| Monetization | — | Free with in-app purchases |
| Size | 34 MB | 43 MB |
| Requires iOS | **15.6** | 16.4 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [CDK CO.PARTNER LLC](https://appshunter.io/developer/1807967691) | [南京五脉生物科技有限公司](https://appshunter.io/developer/6771737025) |

## What reviewers say

### Contextionary App

[App page](https://appshunter.io/ios/app/contextionary-app/id6758235755)

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Unlimited Words | $4.99 | per month |
| Unlimited Words | $19.99 | per year |


### AI错题树

[App page](https://appshunter.io/ios/app/ai/id6771737023)

Effortlessly capture and analyze your mistakes from tests and homework using AI. Organize errors by subject and type, receive correct problem-solving approaches, and track your learning progress to identify weak areas.

**Highlights:** Photo upload for questions and test papers, AI error diagnosis and correction guidance, Organize mistakes by subject and error type, Track learning progress and identify weak areas, Privacy protection with local AI analysis

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 100 AI calls | $0.99 | one-time |
| 1000 AI Calls | $4.99 | one-time |
| 5000 AI Calls | $24.99 | one-time |


## Frequently asked questions

### Is Contextionary App free?

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

### Is AI错题树 free?

AI错题树 is free to download, with in-app purchases available.

### Do Contextionary App or AI错题树 have ads?

Neither Contextionary App nor AI错题树 shows ads.

### Which is updated more often, Contextionary App or AI错题树?

Contextionary App ships an update every 2 days, and AI错题树 every 10 days. Most recently, Contextionary App was updated on September 10, 2026 and AI错题树 on September 21, 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.*