# Ruler - Accurate Ruler

> Accurate digital ruler based on device screen width. (iPhone/iPad app by 祥祎 刘.)

- Source: https://appshunter.io/ios/app/ruler-accurate-ruler/id1084232739 (this page in markdown: same URL + `.md`)
- Developer: [祥祎 刘](https://appshunter.io/developer/1071522659)
- Category: Productivity, Utilities
- Price: Free
- Rating: 2.60/5 from 40 App Store ratings · 96 written reviews indexed
- Age rating: 4+
- Requires: iOS 15.6 · 4 MB
- Languages: American English, Chinese (Simplified, China), Chinese (Traditional, Taiwan)
- Released: 2016-02-18
- Data updated: 2026-08-17
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/ruler-accurate-ruler/id1084232739/reviews.md

## What is Ruler?

You may already noticed that most of ruler apps are actually wrong.

Accurate Ruler renders according to screen width spec of the device that your are currently using. So It is accurate. 
Already tested in following devices including: 
iPhone X, XR, XS, Max
All sizes of iPad 2019
iPhone 4
iPhone 4s
iPhone 5
iPhone 5s
iPhone 5c
iPhone 6
iPhone 6 plus
iPhone 6s
iPhone 6s plus
iPhone se
iPhone 7
iPhone 7 plus
iPad 2
iPad 3
iPad 4
iPad air
iPad air 2
iPad mini
iPad min 2
iPad min 3
iPad mini 4
iPad p​​ro, 
iPod Touch 5/6 
If your device is one of them, we insure it is accurate.

## Key features

- Accurate screen-based rendering
- Device-specific calibration
- Wide device compatibility
- Precise measurement tool

## What do users think of Ruler?

Overall sentiment: mixed

**Pros**

- ✅ Accurate measurements compared to physical rulers
- 👍 Simple and intuitive user interface
- 🎯 No intrusive ads or minimal advertising
- ⚡ Fast and responsive performance
- 🆓 Free to use application
- 📱 Works well on older iPhone models (6S, 6+, 7)
- 🎨 Clean and minimalist design

**Cons**

- 🐛 Blank white screen on newer devices
- ❌ No support for iPhone 12 and newer models
- ❌ No support for iPhone X and iPhone 11
- 🔄 App not updated in years
- ⚠️ Device compatibility detection issues
- 🔐 Privacy concerns - clipboard access without permission
- 📐 Inaccurate measurements on some devices
- 🔧 Broken toggle switches and non-functional UI elements
- 💰 Misleading free app that charges users
- 📱 iPad compatibility issues

**Commonly reported bugs**

- White/blank screen display on newer iOS versions
- App crashes and freezes on launch
- Ruler not rendering or displaying
- Toggle switches stuck in grey/disabled state
- Incorrect device identification (iPad size misidentification)
- Incompatibility with iOS 13.3 and newer
- Authenticator code clipboard access on launch
- Screen rotation issues
- Inaccurate ruler scaling on iPhone 8, 11, 12, 13, 16 Pro
- App requests rating before allowing use

**Most requested features**

- Support for iPhone 12, 13, 14, 15, 16 and newer models
- Millimeter measurement option
- Longer ruler display
- Fractional inches (1/16, 1/8) instead of decimal inches
- Support for newer iPad models
- Ability to disable ads
- Better device detection and compatibility

## Recent user reviews (10 of 96)

All indexed reviews: https://appshunter.io/ios/app/ruler-accurate-ruler/id1084232739/reviews.md

### 4/5 — Pretty funny interface

*2025-09-21*

When i opened the app i thought it’s sole purpose was to simply tell you that it’s correct about your screen size 😂

### 1/5 — Doesn’t work on iphone 16 pro

*2025-03-05*

Doesn’t work on iphone 16 pro

### 5/5 — Great app

*2024-10-01*

Has worked well for many years and looks nice, thanks!

### 1/5 — Dead

*2024-01-13, version 6.1*

App no longer functions and when launched it requested access to my Authenticator pasted code. The app just displays a white screen, a broken toggle and 3 links. One of those links is just to write a review.

### 1/5 — Used to work fine but it’s broken now

*2023-06-24, version 6.1*

Used to work fine but now there is no ruler on the screen, the app is rotated and all I can ever see is the switch between CM and IN.

### 1/5 — Blank screen

*2023-06-11*

It doesn’t show anything except some buttons like “my other apps” and “write a review” which I used to write this but not a ruler

### 1/5 — Not working

*2023-05-01, version 6.1*

App won’t even let me choose cm or inches there both grey

### 5/5 — nb

*2023-01-16*

nb

### 1/5 — Was excellent but now just a blank screen

*2022-07-15, version 6.1*

This ruler app used to be absolutely perfect. It just worked. It was accurate and showed the ruler instantly. However, it now just shows a blank white screen with no measurements. Please fix it as all the other ruler apps are full of ads and terrible !

### 1/5 — Used to be great now no longer works

*2022-06-16*

I’ve had this ruler app on this phone for a while and suddenly one day decided to not work anymore. Developer is not following through with software updates and the application is no longer functional.

## Frequently asked questions about Ruler

### What does this app do?

This application functions as a digital ruler, providing accurate measurements by rendering based on your specific device's screen width. It aims to be more precise than other ruler apps by calibrating to your device's dimensions.

### How is this ruler accurate?

The app ensures accuracy by rendering the ruler according to the exact screen width specifications of the device you are using. This calibration method is designed to provide a precise measurement tool.

### Is this app free to use?

Yes, this application is completely free to use. There are no in-app purchases or advertisements, offering a straightforward and cost-free measurement experience.

### What devices is this app compatible with?

The app has been tested and confirmed to be accurate on a wide range of Apple devices, including various iPhone, iPad, and iPod Touch models from older to newer generations. A comprehensive list is available in the app's description.

### What are common use cases for this app?

This app is useful for quickly measuring objects around you when you don't have a physical ruler available. It's ideal for tasks requiring approximate lengths, such as checking if an item will fit in a space or comparing sizes.

## Version history (last 5 releases)

### 7.0 — 2025-04-08

Bug fixes and performance improvements for iOS18

### 6.1 — 2019-11-05

Updated for iPhone 11/Pro/Max

### 6.0 — 2019-06-10

Updated for X, XR, XS, Max and all sizes of iPad 2019

### 5.1 — 2016-11-11

updated for iPhone 7 and IOS 10.1

### 5.0 — 2016-10-10

updated for iPhone 7 and IOS 10

## Apps similar to Ruler

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [AR Ruler: Digital Tape Measure](https://appshunter.io/ios/app/ar-ruler-digital-tape-measure/id1326773975) | 4.6 (962) | Free | Productivity |
| [Measuring Tape, Photo Ruler](https://appshunter.io/ios/app/measuring-tape-photo-ruler/id1020133524) | 4.2 (2,610) | Free | Productivity |
| [Ruler Pro - Measuring Tape](https://appshunter.io/ios/app/ruler-pro-measuring-tape/id1497431339) | 4.0 (8) | $1.99 | Productivity |
| [Pro Ruler - Measuring Tape](https://appshunter.io/ios/app/pro-ruler-measuring-tape/id1541122485) | 4.2 (155) | Free | Productivity |
| [Ruler - Scale Ruler](https://appshunter.io/ios/app/ruler-scale-ruler/id919130707) | 3.7 (3) | Free | Productivity |
| [Tape Measure Camera AR Ruler](https://appshunter.io/ios/app/tape-measure-camera-ar-ruler/id1078675465) | 4.2 (775) | Free | Productivity |

## More apps by 祥祎 刘

- [孙子兵法 - 精确原文【有声】免流量](https://appshunter.io/ios/app/id1071522660)
- [史记 - 精确原文系列](https://appshunter.io/ios/app/id1073308500)
- [易经 - 精确原文系列](https://appshunter.io/ios/app/id1075034079)
- [黄帝内经 - 精确原文【有声】免流量](https://appshunter.io/ios/app/id1075767132)
- [论语 - 简、繁、译、英，全版本系列](https://appshunter.io/ios/app/id1075769144)
- [三国演义 - 精确原文【有声】免流量](https://appshunter.io/ios/app/id1080081542)

All apps by 祥祎 刘: https://appshunter.io/developer/1071522659

## Related topics

[accurate ruler](https://appshunter.io/ios/topics/accurate-ruler) · [vertical ruler](https://appshunter.io/ios/topics/vertical-ruler)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-17.*