# 机械考研 vs 21天计划

The clearest difference is in-app purchases: 21天计划 at none against 机械考研's 4. On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. 机械考研 sells 4 one-off in-app purchases. 21天计划 asks for nothing beyond the download.

## The numbers

| Metric | 机械考研 | 21天计划 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Size | 42 MB | 42 MB |
| Requires iOS | 12.0 | 12.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 17+ | 4+ |
| Developer | [湖南欧几里得教育科技有限公司](https://appshunter.io/developer/1343092239) | [红升 孙](https://appshunter.io/developer/1502418960) |

## What reviewers say

### 机械考研

[App page](https://appshunter.io/ios/app/id6744552183)

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 中南大学·真题上岸大礼包 | $14.99 | one-time |
| 河北工业大学·真题上岸大礼包 | $17.99 | one-time |
| 重庆大学(909)·真题上岸大礼包 | $19.99 | one-time |
| 浙大机械考研上岸大礼包 | $39.99 | one-time |


### 21天计划

[App page](https://appshunter.io/ios/app/21/id6754164973)

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

**In-app purchases:** none


## Frequently asked questions

### Is 机械考研 free?

机械考研 is free to download, with in-app purchases available.

### Is 21天计划 free?

21天计划 is free to download, with no in-app purchases.

### Do 机械考研 or 21天计划 have ads?

Neither 机械考研 nor 21天计划 shows ads.

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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.*