# E3BlueLight vs Ruler∘

The clearest difference is update cadence: Ruler∘ at every 2 weeks against E3BlueLight's every 6 weeks. E3BlueLight's advantage is iOS requirement (13.0 vs 17.0). On price, ads, in-app purchases and device support there is nothing between them.

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

E3BlueLight ships an update every 6 weeks, Ruler∘ every 2 weeks. The most recent releases landed on October 14, 2026 and October 3, 2026 respectively.

## The numbers

| Metric | E3BlueLight | Ruler∘ |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.4 (44 ratings)](https://appshunter.io/ios/app/ruler/id1503532937/reviews)** |
| Number of ratings | — | **44** |
| Positive reviews | — | 50.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 weeks | **Every 2 weeks** |
| Monetization | — | Free with in-app purchases |
| Size | 9 MB | 8 MB |
| Requires iOS | **13.0** | 17.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [北京易方通达科技有限公司](https://appshunter.io/developer/889658425) | [Andrei Shpileuski](https://appshunter.io/developer/1471178734) |

## What reviewers say

### E3BlueLight

[App page](https://appshunter.io/ios/app/e3bluelight/id1039337297)

**Features:** macOS Compatibility

**In-app purchases:** none


### Ruler∘

[App page](https://appshunter.io/ios/app/ruler/id1503532937)

This app uses augmented reality to measure distances, lengths, heights, and angles with your device's camera. It offers various modes for accurate measurements on different surfaces and for small objects. Users can save their measurements directly to their camera roll.

**Highlights:** Augmented reality measurements, Measure distance, length, height, area, angles, Point and shoot measurement, Air Mode for linear measurement, Surface Locked for planes, Save measures to Camera Roll

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

**In-app purchases:** none


## Frequently asked questions

### Is E3BlueLight free?

E3BlueLight is free to download, with no in-app purchases.

### Is Ruler∘ free?

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

### Do E3BlueLight or Ruler∘ have ads?

Neither E3BlueLight nor Ruler∘ shows ads.

### Which is updated more often, E3BlueLight or Ruler∘?

E3BlueLight ships an update every 6 weeks, and Ruler∘ every 2 weeks. Most recently, E3BlueLight was updated on October 14, 2026 and Ruler∘ on October 3, 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.*