# iSlideRule — Fully customizable sliderule

> Customizable digital sliderule app for advanced mathematical calculations. (iPhone/iPad app by Reid Performance Designs.)

- Source: https://appshunter.io/ios/app/isliderule/id292884533 (this page in markdown: same URL + `.md`)
- Developer: [Reid Performance Designs](https://appshunter.io/developer/292884536)
- Category: Education, Utilities
- Price: $0.99
- Rating: 5.00/5 from 6 App Store ratings · 21 written reviews indexed
- Age rating: 4+
- Requires: iOS 9.2 · 25 MB
- Languages: American English, Dutch, French (France), German (Germany), Greek, Italian, Japanese, European Portuguese, Russian, European Spanish and 3 more
- Released: 2008-10-10
- Data updated: 2026-06-10
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/isliderule/id292884533/reviews.md

## What is iSlideRule?

iSlideRule is a fully customizable sliderule app supporting multiplication, sines, tangents, cosines, cotangents, roots, squares, logarithms, and hyperbolics.

There are nearly 100 different scales supported by iSlideRule, including scales for dimensional analysis.  From the set of scales provided, 12 can be selected for the top and bottom rules, as well as the slide, in groups of 4 scales each.  Double-tapping each rule selects the next group of 4 within the application.  A two-finger pan left or right on the center slide provides viewing of the index ends, while one finger swiping up or down on the cursor changes color schemes dynamically.

The application supports rotation of the handheld, allowing the sliderule to take full advantage of the display, and has 11 selectable color schemes to customize your sliderule to your favorite color.

## Key features

- Multiplication, sines, tangents, cosines, cotangents, roots, squares, logarithms, hyperbolics
- Nearly 100 different scales, including dimensional analysis
- Selectable scales for top, bottom rules, and slide
- Dynamic color scheme customization
- Supports device rotation
- Index end viewing and cursor color change

## Recent user reviews (10 of 21)

All indexed reviews: https://appshunter.io/ios/app/isliderule/id292884533/reviews.md

### 4/5 — Nice ideas, flawed usability

*2025-09-14*

This app has flexible scale configs and lots of special tick marks but it feels neglected. It needs updates to be usable on iPhones since ca. 2020.
- Scale labels are obscured by the notch or dynamic island.
- In the default portrait orientation more than half the screen is left empty.  Instead, a full-height view would be useful and constitute a mild zoom feature that is otherwise missing.
- Settings and Help buttons are clipped in landscape orientation.
- The ‘Help’ button links to a non-SSL web page which prompts a security alert (disputable as those are, they deter users). This is unexpected given the large download size of already above 20MB.

### 5/5 — To the developer: Could you…?

*2023-08-14*

Hello there! I, like every person that has reviewed your app, love what you have done with it!

However, allow me to suggest an improvement:  Would it be possible to move/alter both the Portrait and Landscape orientation implementations so that the Dynamic Island does not intrude with the display? That would make your app a 5+ star app.

### 5/5 — Great tool

*2023-06-18*

I too am a slide rule collector and student. This app is very customizable and intuitive. I can set it up to match many of my grandfather’s old slide rules. Also has a great description area.  But what I love most is that this app does not track any of your information. Good job!!

### 5/5 — Very well made

*2019-06-03*

Makes best use of screen. All seems to work as it should. I'm a slide rule collector, so nice to have good one on mobile device. The only iPhone slide rule app I know of which has trig scales. Well done!

### 5/5 — If you're “into” slide rules ...

*2016-03-20*

This is the best out there. Math “purists” will love it.

### 3/5 — Cursor positioning issues

*2013-05-06, version 1.2.2*

The issues are similar to the HD version, except that the nudge feature randomly seems to get stuck nudging in the same direction in both portrait and landscape orientation. The Display Values option is irritating on small devices, since it appears to be impossible to adjust the cursor in increments as small as the displayed precision indicates (for example, 1.201 is as close as you are going to get the cursor to 1.2 on the D scale).

### 5/5 — Okay, so it

*2011-03-23*

...but it's a nice toy, and the incongruity of having a slide rule built into an iPod is simply irresistable.  And it's a functional slide rule, to boot, not just a joke.

### 5/5 — Best slide rule app

*2010-10-26, version 0*

This is simply the best slide rule app i've tried, does everything that my old physical rule did and much more - clearly designed by someone who knows about using a slide rule instead of a calculator.

### 3/5 — good start, needs improvement

*2010-08-23*

The app looks great and works well, but there is a serious limitation. When working with a slide rule three things need to be quickly visible: the cursor, and both ends. Currently you have to (slowly) scroll to see the ends, and that moves the cursor. It would greatly improve the usefulness of the app if you could simply flick to the ends. Otherwise a great start. Looking forward its being really useful.

### 5/5 — Version 1.1.0 Comes Through!

*2010-08-19*

I downloaded this app half a year ago, and while I was impressed with a lot of things about it... slide movement, graphics, scales to choose from... the inability to rearrange scales, especially having C above D on the slide and stator respectively, made it fall short. The developer promised an update was in the works, and he really came through with this one. Outstanding implementation of a slide rule on an iPod/iPhone interface. A solid 5 stars, and worth waiting for.

## Frequently asked questions about iSlideRule

### What mathematical functions does iSlideRule support?

iSlideRule supports a comprehensive set of functions including multiplication, sines, tangents, cosines, cotangents, roots, squares, logarithms, and hyperbolics, making it a versatile tool for various calculations.

### How many scales are available in iSlideRule?

The app offers nearly 100 different scales, including specialized scales for dimensional analysis, allowing for a wide range of applications and calculations.

### Can I customize the appearance of iSlideRule?

Yes, iSlideRule features 11 selectable color schemes that can be dynamically changed by swiping up or down on the cursor, allowing for personalized customization.

### What devices is iSlideRule compatible with?

iSlideRule is designed for iPhone and iPod devices, supporting rotation to take full advantage of the display.

### How does iSlideRule handle different groups of scales?

You can select scales for the top and bottom rules, as well as the slide, in groups of 4. Double-tapping each rule allows you to cycle through these groups.

### What is the user sentiment for iSlideRule based on ratings?

Based on 6 ratings, iSlideRule has achieved a perfect 5.0-star rating, indicating very positive user sentiment and satisfaction with its functionality.

### Does iSlideRule have ads?

No, iSlideRule does not contain advertisements, providing an uninterrupted user experience for its paid features.

### When was iSlideRule last updated?

The latest version of iSlideRule, 3.1.2, was last updated on April 14, 2022, indicating ongoing support and maintenance.

## Version history (last 5 releases)

### 3.1.2 — 2022-04-14

Update to correct an issue when running on iPad

### 3.1.1 — 2022-04-12

Updated handling of initial default settings

### 3.1.0 — 2022-04-09

Updated CIF and DIF scales to correct an offset error.
Added ES and Faber-Castell scale coloring options.
Migrated application guide to website.
Added scales for hyperbolic trigs, iSTd, N1-N4, and 1/N1-1/N4.

### 3.0.0 — 2019-02-25

Updated errors in the integrated help documents. Updated app to provide better support of latest iOS versions, as well as newer device models.

### 2.2.0 — 2015-08-11

Added ability to change/configure settings within the application.
Removed iSlideRule from the normal system settings application.

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## More apps by Reid Performance Designs

- [iSlideRuleHD](https://appshunter.io/ios/app/isliderulehd/id473519866)

All apps by Reid Performance Designs: https://appshunter.io/developer/292884536

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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 2026-06-10.*