# Protractor Edge vs ECO

The clearest difference is in-app purchases: ECO at none against Protractor Edge's 2. ECO also leads on ads (none vs shown) and update cadence (every 10 months vs every 43 months). Protractor Edge's advantage is iOS requirement (9.0 vs 13.0). On price and device support there is nothing between them.

Both are free to download. Protractor Edge sells 2 in-app purchases, starting at $1.99 per year. ECO asks for nothing beyond the download.

Protractor Edge ships an update every 43 months, ECO every 10 months. The most recent releases landed on October 16, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | Protractor Edge | ECO |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (55 ratings)](https://appshunter.io/ios/app/protractor-edge-clinometer/id1198499762/reviews)** | — |
| Number of ratings | **55** | — |
| Positive reviews | 69.6% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 43 months | **Every 10 months** |
| Monetization | Freemium | — |
| Size | 21 MB | 41 MB |
| Requires iOS | **9.0** | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 17+ |
| Developer | [嵩 张](https://appshunter.io/developer/1091921941) | [CHIH BIN CHEN](https://appshunter.io/developer/1828080151) |

## What reviewers say

### Protractor Edge

[App page](https://appshunter.io/ios/app/protractor-edge-clinometer/id1198499762)

Measure angles directly on your device without taking photos or placing the angle on screen. This app offers a unique and efficient way to determine degrees, saving you time with its handy assistant functionality.

**Highlights:** Direct angle measurement on device, Intuitive line dragging interface, Measures angles in photos (Premium), Measures from camera view (Premium), Ad-free experience (Premium)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Access | $1.99 | per year |
| Remove Ads | $0.99 | one-time |


### ECO

[App page](https://appshunter.io/ios/app/eco-link-pro/id6749229977)

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

**In-app purchases:** none


## Frequently asked questions

### Is Protractor Edge free?

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

### Is ECO free?

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

### Do Protractor Edge or ECO have ads?

Protractor Edge shows ads; ECO does not.

### Which is updated more often, Protractor Edge or ECO?

Protractor Edge ships an update every 43 months, and ECO every 10 months. Most recently, Protractor Edge was updated on October 16, 2026 and ECO on October 7, 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.*