# OPie Mohr's Circle — 2D/3D Shear, Stress Solver

> 2D and 3D Mohr's Circle calculation and visualization tool. (iPhone/iPad app by Andrew Swenson.)

- Source: https://appshunter.io/ios/app/opie-mohrs-circle/id1581023550 (this page in markdown: same URL + `.md`)
- Developer: [Andrew Swenson](https://appshunter.io/developer/1558926423)
- Category: Utilities, Reference
- Price: Free with in-app purchases
- Rating: 5.00/5 from 8 App Store ratings
- Age rating: 4+
- Requires: iOS 14.5 · 7 MB
- Languages: American English
- Released: 2021-09-12
- Data updated: 2026-06-10
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/opie-mohrs-circle/id1581023550/reviews.md

## What is OPie Mohr's Circle?

Perform and visualize both 2D and 3D Mohr's Circle calculations.

## Key features

- 2D Mohr's Circle calculations
- 3D Mohr's Circle calculations
- Shear stress visualization
- Stress analysis
- Engineering calculations

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Remove Ads | $1.99 | one-time |



## Frequently asked questions about OPie Mohr's Circle

### What is OPie Mohr's Circle used for?

OPie Mohr's Circle is used to perform and visualize 2D and 3D Mohr's Circle calculations, which are essential for understanding shear and stress in engineering.

### What devices does OPie Mohr's Circle support?

OPie Mohr's Circle is available on iPhone, iPad, and iPod devices.

### How often is OPie Mohr's Circle updated?

The latest version, 1.6, was released on November 19, 2021. The app was initially released on September 12, 2021.

### What is the age rating for OPie Mohr's Circle?

OPie Mohr's Circle has an age rating of 4+, making it suitable for a wide range of users.

### What is the user rating for OPie Mohr's Circle?

OPie Mohr's Circle has an excellent rating of 5.0 stars based on 8 user reviews.

### Is OPie Mohr's Circle free to use?

Yes, OPie Mohr's Circle is free to download and use. It also offers in-app purchases.

### Who developed OPie Mohr's Circle?

OPie Mohr's Circle was developed by Andrew Swenson.

## Version history (last 5 releases)

### 1.6 — 2021-11-19

one more fix to the tab bar when launching app from the background

### 1.5 — 2021-11-13

improved: layout between having the tab bar present or swiped away.
improved: in app purchase for removing advertising does require restarting the app
improved: 3D Mohrs Circle slider buttons colored to match the data in the chart
improved: removed the all chart lines and axis since they are not required.  Also removed the user chart interaction so that you can swipe up or down to remove the tab bar from anywhere on the screen.  Without doing this, swipe gestures would not be recognized on the chart.
fixed: axis hold button labels so that the text is always displayed
fixed: funny tab bar behavior when either changing between dark and light mode or putting the app into background and recalling it.

### 1.4 — 2021-10-26

fixed: minor bugs including improved layout

### 1.3 — 2021-10-12

fixed: info page tabBar overlap
added: remove Ads (In-App Purchase)

### 1.2 — 2021-09-27

added: capability to swipe the tab bar on and off the display.  Swipe anywhere on the display except the chart area to hide or display the tab bar.  This will give you a larger keyboard.

## Apps similar to OPie Mohr's Circle

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Mohr's Circle](https://appshunter.io/ios/app/mohrs-circle/id395110520) | 3.3 (3) | $5.99 | Utilities |
| [Mechanical Engineering Toolkit](https://appshunter.io/ios/app/mechanical-engineering-toolkit/id1601099443) | 4.8 (50) | Free | Utilities |
| [Pressure Vessel Pro](https://appshunter.io/ios/app/pressure-vessel-pro/id535696875) | 5.0 (1) | $5.99 | Utilities |
| [Vector Calculator Plus](https://appshunter.io/ios/app/vector-calculator-plus/id1630864948) | 4.0 (1) | $2.99 | Utilities |
| [Beam Engineering lite](https://appshunter.io/ios/app/beam-engineering-lite/id1048358824) | 4.4 (32) | Free | Utilities |
| [Mechanical Engineering Calc](https://appshunter.io/ios/app/mechanical-engineering-calc/id1281858515) | — | Free | Utilities |

## More apps by Andrew Swenson

- [OPie Isentropic Calculator](https://appshunter.io/ios/app/opie-isentropic-calculator/id1558926421)
- [OPie RPN Calculator](https://appshunter.io/ios/app/opie-rpn-calculator/id1559116337)
- [OPie RetireFIRE](https://appshunter.io/ios/app/opie-retirefire/id1562734440)
- [OPie Unit Converter](https://appshunter.io/ios/app/opie-unit-converter/id1570481314)
- [OPie Tip Calc](https://appshunter.io/ios/app/opie-tip-calc/id1570900875)

All apps by Andrew Swenson: https://appshunter.io/developer/1558926423

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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.*