# AI Dr. J vs Ballet Protractor

The clearest difference is ads: AI Dr. J at none against Ballet Protractor's shown. Ballet Protractor's advantage is update cadence (daily vs monthly). On price, in-app purchases, device support and iOS requirement there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

AI Dr. J ships an update monthly, Ballet Protractor daily. The most recent releases landed on October 30, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | AI Dr. J | Ballet Protractor |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Monthly | **Daily** |
| Size | 36 MB | 60 MB |
| Requires iOS | **15.1** | 15.5 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 12+ | 4+ |
| Developer | [Cura-Pulse Co., Ltd](https://appshunter.io/developer/1861708804) | [Jungmun Choi](https://appshunter.io/developer/1877873773) |

## What reviewers say

### AI Dr. J

[App page](https://appshunter.io/ios/app/ai-dr-j/id6756600573)

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

**In-app purchases:** none


### Ballet Protractor

[App page](https://appshunter.io/ios/app/ballet-protractor-leg-angle/id6782101611)

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

**In-app purchases:** none


## Frequently asked questions

### Is AI Dr. J free?

AI Dr. J is free to download, with no in-app purchases.

### Is Ballet Protractor free?

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

### Do AI Dr. J or Ballet Protractor have ads?

Ballet Protractor shows ads; AI Dr. J does not.

### Which is updated more often, AI Dr. J or Ballet Protractor?

AI Dr. J ships an update monthly, and Ballet Protractor daily. Most recently, AI Dr. J was updated on October 30, 2026 and Ballet Protractor on October 31, 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.*