# Protractor vs U Hydrogen Connect

The clearest difference is in-app purchases: U Hydrogen Connect at none against Protractor's 6. U Hydrogen Connect also leads on update cadence (weekly vs every 5 weeks) and iOS requirement (13.0 vs 17.0). On price, ads and device support there is nothing between them.

Both are free to download. Protractor sells 6 in-app purchases, starting at $4.99 per month. U Hydrogen Connect asks for nothing beyond the download.

Protractor ships an update every 5 weeks, U Hydrogen Connect weekly. The most recent releases landed on October 18, 2026 and September 21, 2026 respectively.

## The numbers

| Metric | Protractor | U Hydrogen Connect |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.8 (6 ratings)](https://appshunter.io/ios/app/protractor-measure-angles/id1601838509/reviews)** | — |
| Number of ratings | **6** | — |
| Positive reviews | 63.6% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 5 weeks | **Weekly** |
| Monetization | Free with in-app purchases | — |
| Size | 7 MB | 25 MB |
| Requires iOS | 17.0 | **13.0** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Noadit, Inc.](https://appshunter.io/developer/1516754355) | [Jung-Kuei Chang](https://appshunter.io/developer/1554218063) |

## What reviewers say

### Protractor

[App page](https://appshunter.io/ios/app/protractor-measure-angles/id1601838509)

Measure angles precisely using your phone's screen, gyroscope, or camera. Offers smart presets, real-time feedback with high accuracy, and calibration features to adapt to various situations.

**Highlights:** 3-in-1 measurement modes, Smart angle presets with alerts, Hyper-responsive feedback (≤0.5° accuracy), Auto dynamic compensation calibration, Anti-shake technology for motion scenes, Screen lock for measurements

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

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| VIP | $4.99 | per month |
| Bubble Tea | $0.99 | one-time |
| Sponsor | $4.99 | one-time |
| Coffee | $4.99 | one-time |
| Sponsor | $19.99 | one-time |
| Sponsor | $99.99 | one-time |


### U Hydrogen Connect

[App page](https://appshunter.io/ios/app/u-hydrogen-connect/id6794296030)

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

**In-app purchases:** none


## Frequently asked questions

### Is Protractor free?

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

### Is U Hydrogen Connect free?

U Hydrogen Connect is free to download, with no in-app purchases.

### Do Protractor or U Hydrogen Connect have ads?

Neither Protractor nor U Hydrogen Connect shows ads.

### Which is updated more often, Protractor or U Hydrogen Connect?

Protractor ships an update every 5 weeks, and U Hydrogen Connect weekly. Most recently, Protractor was updated on October 18, 2026 and U Hydrogen Connect 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.*