# i vs Ruler

The clearest difference is rating: Ruler at 4.3 against i's 2.4. Ruler also leads on ratings volume (133 vs 14) and iOS requirement (11.0 vs 16.0). i's advantage is in-app purchases (none vs 2) and ads (none vs shown). On price, update cadence and device support there is nothing between them.

Both are free to download. Ruler sells 2 in-app purchases, starting at $1.99 per 7 days. i asks for nothing beyond the download.

Ruler holds the better App Store score, 4.3 against 2.4. That said, the two scores are not equally well evidenced: Ruler has 133 ratings behind it against 14, so its average is the more settled of the two. Written reviews complicate that: 50% of i's written reviews are positive against 33% of Ruler's, so the app with the better star average is not the one people write more warmly about.

i ships an update every 14 months, Ruler every 7 months. The most recent releases landed on June 1, 2026 and August 20, 2026 respectively.

## The numbers

| Metric | i | Ruler |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.4 (14 ratings)](https://appshunter.io/ios/app/i-scale/id926099803/reviews) | **[4.3 (133 ratings)](https://appshunter.io/ios/app/ruler-measuring-scale/id1449113794/reviews)** |
| Number of ratings | 14 | **133** |
| Positive reviews | **50.0% of reviews** | 33.3% of reviews |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 14 months | **Every 7 months** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 5 MB | 32 MB |
| Requires iOS | 16.0 | **11.0** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Shanghai Qingying Electronic Technology LLC](https://appshunter.io/developer/926099802) | [MD KHAIRUL ISLAM](https://appshunter.io/developer/1445424899) |

## What reviewers say

### i

[App page](https://appshunter.io/ios/app/i-scale/id926099803)

Transform your microscope into a digital one using your phone and a special adapter. Capture images with embedded scale bars and annotations, then easily share them with others.

**Highlights:** Capture digital micrographs, Support magnification up to 5 objectives, Scale-bar embedding and calibration, Stamp remarks, date/time, magnification, Direct email and message sharing

**Features:** macOS Compatibility

**In-app purchases:** none


### Ruler

[App page](https://appshunter.io/ios/app/ruler-measuring-scale/id1449113794)

This utility app uses augmented reality to measure the length and area of real-world objects using your smartphone's camera. It offers unlimited measurements and an ad-free experience with premium subscriptions.

**Highlights:** Augmented reality measurement, Measure length and area, High precision with AR Kit, Unlimited measurements (premium), Ad-free experience (premium), Subscription options available

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Ruler Premium Weekly | $1.99 | per 7 days |
| Ruler Monthly Premium | $5.99 | per month |


## Frequently asked questions

### Is i free?

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

### Is Ruler free?

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

### Which has better reviews, i or Ruler?

Ruler is rated higher. i averages 2.4 out of 5 from 14 ratings, while Ruler averages 4.3 from 133 ratings.

### Do i or Ruler have ads?

Ruler shows ads; i does not.

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

i ships an update every 14 months, and Ruler every 7 months. Most recently, i was updated on June 1, 2026 and Ruler on August 20, 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.*