# Ruler vs E

The clearest difference is ads: E at none against Ruler's shown. E also leads on iOS requirement (12.0 vs 17.0). Ruler's advantage is update cadence (every 3 weeks vs every 6 months). On price, 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.

Ruler ships an update every 3 weeks, E every 6 months. The most recent releases landed on November 1, 2026 and November 2, 2026 respectively.

## The numbers

| Metric | Ruler | E |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.5 (79 ratings)](https://appshunter.io/ios/app/ruler-cm-mm-inches/id1022857549/reviews)** | — |
| Number of ratings | **79** | — |
| Positive reviews | 40.0% of reviews | — |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | **Every 3 weeks** | Every 6 months |
| Monetization | Free with in-app purchases | — |
| Size | 9 MB | 53 MB |
| Requires iOS | 17.0 | **12.0** |
| Devices | **iPhone, iPad** | iPad |
| Age rating | 4+ | 17+ |
| Developer | [Noadit, Inc.](https://appshunter.io/developer/1516754355) | [XinGuang Technology Co.,Ltd.](https://appshunter.io/developer/1130851011) |

## What reviewers say

### Ruler

[App page](https://appshunter.io/ios/app/ruler-cm-mm-inches/id1022857549)

Measure lengths, widths, and diagonals accurately using your phone. Switch between metric and imperial units, and utilize flexible starting points for precise measurements in any direction. Features auto-calibration for minimal error and a screen lock to preserve readings.

**Highlights:** Multi-mode measurement (CM, MM, Inches, Fractions), Flexible starting points, Full-direction measurement (horizontal, vertical, diagonal), Auto-calibration for accuracy, Screen lock for preserving readings, Ad-free VIP option

**In-app purchases:** none

**What reviewers like**

- 👍 Simple and easy to use
- 📏 Accurate measurements (for some)
- 💡 Useful for small objects
- ✨ Clean interface
- 🚀 Fluid performance

**What reviewers complain about**

- 😠 Excessive and intrusive ads
- 🚫 Ads block measurements
- 🔊 Loud and shocking ads
- 💸 No option to pay for ad-free (or purchase lost)
- 📉 Inaccurate inch measurements (decimal vs. fractional)

**Reported bugs**

- Ads pop up constantly, making app unusable
- Ads overlay the ruler/measurements
- App crashes constantly
- Black screen issue
- Inaccurate measurements (especially inches)

**Requested features**

- Option to remove ads via one-time purchase
- Ability to calibrate the ruler
- Offset crosshairs to see numbers
- Fractional inch (1/8, 1/16) display option
- Option to hide ruler digits


### E

[App page](https://appshunter.io/ios/app/e-lab-or/id1431245027)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Ruler free?

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

### Is E free?

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

### Do Ruler or E have ads?

Ruler shows ads; E does not.

### Which is updated more often, Ruler or E?

Ruler ships an update every 3 weeks, and E every 6 months. Most recently, Ruler was updated on November 1, 2026 and E on November 2, 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.*