# 优学错题本 vs 光合动力

The clearest difference is device support: 光合动力 at 2 against 优学错题本's —. 优学错题本's advantage is iOS requirement (11.0 vs 16.6). On price and in-app purchases there is nothing between them.

Both are free to download. 优学错题本 sells 3 in-app purchases, starting at $1.99 per 7 days and 光合动力 sells 2 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

## The numbers

| Metric | 优学错题本 | 光合动力 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | — | No |
| Size | 25 MB | 11 MB |
| Requires iOS | **11.0** | 16.6 |
| Devices | — | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [清清 孔](https://appshunter.io/developer/1740686855) | [贝贝 尚](https://appshunter.io/developer/1735265297) |

## What reviewers say

### 优学错题本

[App page](https://appshunter.io/ios/app/id6664059614)

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 周会员 | $1.99 | per 7 days |
| 月会员 | $3.99 | per month |
| 年会员 | $19.99 | per year |


### 光合动力

[App page](https://appshunter.io/ios/app/id6761237684)

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 连续包月 | $1.99 | per month |
| 连续包年 | $14.99 | per year |


## Frequently asked questions

### Is 优学错题本 free?

优学错题本 is free to download, with in-app purchases available.

### Is 光合动力 free?

光合动力 is free to download, with in-app purchases available.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*