# Protractor vs KeyLingo 키링고

The clearest difference is in-app purchases: KeyLingo 키링고 at none against Protractor's 3. On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Protractor sells 3 in-app purchases, starting at $4.99 per 7 days. KeyLingo 키링고 asks for nothing beyond the download.

Protractor ships an update every 6 weeks, KeyLingo 키링고 every 4 weeks. The most recent releases landed on October 3, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | Protractor | KeyLingo 키링고 |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 6 weeks | **Every 4 weeks** |
| Monetization | — | Freemium |
| Size | 5 MB | 6 MB |
| Requires iOS | 17.0 | **16.0** |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [Phuc Pham](https://appshunter.io/developer/1893081423) | [SLAM Co.](https://appshunter.io/developer/6791572291) |

## What reviewers say

### Protractor

[App page](https://appshunter.io/ios/app/protractor-angle-finder/id6772273661)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Incline Gauge Weekly | $4.99 | per 7 days |
| Roof Pitch Yearly | $24.99 | per year |
| Bevel & Degree, Pay Once | $49.99 | one-time |


### KeyLingo 키링고

[App page](https://appshunter.io/ios/app/keylingo/id6791572288)

Translate messages in real-time without switching apps. This keyboard app displays translations directly as you type, allowing for instant insertion with a single tap. Communicate seamlessly across languages in any application.

**Highlights:** Real-time translation as you type, One-tap translation insertion, Use in any app with a keyboard, Tone adjustment (Pro feature), No app switching required

**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 KeyLingo 키링고 free?

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

### Do Protractor or KeyLingo 키링고 have ads?

Neither Protractor nor KeyLingo 키링고 shows ads.

### Which is updated more often, Protractor or KeyLingo 키링고?

Protractor ships an update every 6 weeks, and KeyLingo 키링고 every 4 weeks. Most recently, Protractor was updated on October 3, 2026 and KeyLingo 키링고 on October 8, 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.*