# 中山七院 vs SmileDiary

The clearest difference is in-app purchases: 中山七院 at none against SmileDiary's 3. 中山七院 also leads on iOS requirement (9.0 vs 17.0). SmileDiary's advantage is device support. On price there is nothing between them.

Both are free to download. SmileDiary sells 3 in-app purchases, starting at $2.99 per month. 中山七院 asks for nothing beyond the download.

## The numbers

| Metric | 中山七院 | SmileDiary |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | — | No |
| Update frequency | — | Every 5 days |
| Monetization | — | Freemium |
| Size | 20 MB | 12 MB |
| Requires iOS | **9.0** | 17.0 |
| Devices | — | **iPhone, Apple Watch** |
| Age rating | 17+ | 4+ |
| Developer | [温州医科大学附属第一医院](https://appshunter.io/developer/1166763743) | [Nanjing Xiaowei Technology Co., Ltd.](https://appshunter.io/developer/1831757763) |

## What reviewers say

### 中山七院

[App page](https://appshunter.io/ios/app/id1318632126)

**In-app purchases:** none


### SmileDiary

[App page](https://appshunter.io/ios/app/smilediary-aligner-tracker/id6753011249)

This app helps you track your clear aligner treatment privately and securely. It offers a smart wear timer, visual calendar, progress photos, and detailed insights into your compliance, all without collecting your personal data.

**Highlights:** Private data storage, No registration required, Smart wear timer, Visual compliance calendar, Guided progress photos, Detailed treatment insights, Data export functionality

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| SmileDiary Pro Monthly | $2.99 | per month |
| SmileDiary Pro Annual | $12.99 | per year |
| SmileDiary Pro Lifetime | $19.99 | one-time |


## Frequently asked questions

### Is 中山七院 free?

中山七院 is free to download, with no in-app purchases.

### Is SmileDiary free?

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

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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.*