# Ruler vs IoTシステム A･ISys

The clearest difference is in-app purchases: IoTシステム A･ISys at none against Ruler's 1. IoTシステム A･ISys also leads on ads (none vs shown). On price, update cadence, device support and iOS requirement there is nothing between them.

Both are free to download. Ruler sells 1 one-off in-app purchase. IoTシステム A･ISys asks for nothing beyond the download.

Ruler ships an update every 5 months, IoTシステム A･ISys every 7 months. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | Ruler | IoTシステム A･ISys |
| --- | --- | --- |
| 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 7 months |
| Monetization | Free with in-app purchases | — |
| Size | 4 MB | 53 MB |
| Requires iOS | **15.0** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [mitsunori oishi](https://appshunter.io/developer/905649994) | [ACTN K.K.](https://appshunter.io/developer/1519939443) |

## 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 |


### IoTシステム A･ISys

[App page](https://appshunter.io/ios/app/iot-aisys/id1615943586)

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

**In-app purchases:** none


## Frequently asked questions

### Is Ruler free?

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

### Is IoTシステム A･ISys free?

IoTシステム A･ISys is free to download, with no in-app purchases.

### Do Ruler or IoTシステム A･ISys have ads?

Ruler shows ads; IoTシステム A･ISys does not.

### Which is updated more often, Ruler or IoTシステム A･ISys?

Ruler ships an update every 5 months, and IoTシステム A･ISys every 7 months. Most recently, Ruler was updated on November 1, 2026 and IoTシステム A･ISys on November 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.*