# Ruler vs CAL_

The clearest difference is in-app purchases: CAL_ at none against Ruler's 1. CAL_ also leads on ads (none vs shown) and update cadence (every 4 days vs every 5 months). On price and device support there is nothing between them.

Both are free to download. Ruler sells 1 one-off in-app purchase. CAL_ asks for nothing beyond the download.

Ruler ships an update every 5 months, CAL_ every 4 days. The most recent releases landed on November 1, 2026 and October 29, 2026 respectively.

## The numbers

| Metric | Ruler | CAL_ |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.7 (3 ratings)](https://appshunter.io/ios/app/ruler-scale-ruler/id919130707/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 63.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 5 months | **Every 4 days** |
| Monetization | Free with in-app purchases | — |
| Size | 4 MB | 9 MB |
| Requires iOS | 15.0 | **12.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [mitsunori oishi](https://appshunter.io/developer/905649994) | [SQUAIR Inc.](https://appshunter.io/developer/1162347955) |

## What reviewers say

### Ruler

[App page](https://appshunter.io/ios/app/ruler-scale-ruler/id919130707)

This app displays various measurement scales for length, including meters and inches. It allows users to set magnification ratios and reduced scales for different applications. Users can calibrate the ruler and adjust PPI settings for accurate measurements.

**Highlights:** Display various measurement scales, Set magnification ratios, Set reduced scales, Measure in meters and inches, Free mode for custom scales, Calibration for accuracy, PPI setting

**Features:** macOS Compatibility, Family Sharing

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Hide Ads | $0.99 | one-time |


### CAL_

[App page](https://appshunter.io/ios/app/cal-logging-calculator/id1162347956)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Ruler free?

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

### Is CAL_ free?

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

### Do Ruler or CAL_ have ads?

Ruler shows ads; CAL_ does not.

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

Ruler ships an update every 5 months, and CAL_ every 4 days. Most recently, Ruler was updated on November 1, 2026 and CAL_ on October 29, 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.*