# Four vs Circuitry

The clearest difference is rating: Four at 4.7 against Circuitry's 3.9. Four also leads on review sentiment (92% vs 51%) and iOS requirement (8.0 vs 12.0). On price, ratings volume, update cadence and ads there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Four holds the better App Store score, 4.7 against 3.9. Both are backed by a comparable volume of ratings — 89 and 156 respectively. Written reviews point the same way: 92% of Four's written reviews are positive against 51% of Circuitry's.

Four ships an update every 7 months, Circuitry every 4 months. The most recent releases landed on October 15, 2026 and October 21, 2026 respectively.

## The numbers

| Metric | Four | Circuitry |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (89 ratings)](https://appshunter.io/ios/app/four-stroke-otto-engine-3d/id1376010957/reviews)** | [3.9 (156 ratings)](https://appshunter.io/ios/app/circuitry-3d-circuit-builder/id1476733898/reviews) |
| Number of ratings | 89 | **156** |
| Positive reviews | **92.0% of reviews** | 51.4% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 4 months** |
| Monetization | Free | Free |
| Size | 183 MB | 35 MB |
| Requires iOS | **8.0** | 12.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [MOZAIK Education Ltd.](https://appshunter.io/developer/1064850236) | [Raffael Kaehn](https://appshunter.io/developer/1234032836) |

## What reviewers say

### Four

[App page](https://appshunter.io/ios/app/four-stroke-otto-engine-3d/id1376010957)

Explore the inner workings of a four-stroke Otto engine through interactive 3D animations. This app offers an engaging way to learn about automotive technology with features like rotation, zooming, and predefined views. It's designed for students but enjoyable for all ages, with multilingual support and VR capabilities.

**Highlights:** Interactive 3D engine model, Rotate, zoom, and pan views, Predefined navigation angles, Multilingual support, VR mode compatibility, Built-in animations and narrations

**Features:** macOS Compatibility

**In-app purchases:** none


### Circuitry

[App page](https://appshunter.io/ios/app/circuitry-3d-circuit-builder/id1476733898)

Build and simulate electronic circuits in an intuitive 3D environment. This app offers lightning-fast analysis and a user-friendly interface, making complex engineering accessible. Circuits are saved as documents for easy sharing and management across devices.

**Highlights:** 3D circuit building, GPU-accelerated analysis, Intuitive 3D interface, Document-based circuit files, Component placement and connection, Resistor, voltage source, light bulb components

**Features:** Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 💡 Cool game idea
- 👍 Nice and 3D interface
- 🚀 Easy to use and perfect 3D
- 👍 Fun and simple
- 👍 Beautifully visual and interactive

**What reviewers complain about**

- 😞 Missing many components
- 😞 Limited functionality
- 😞 Not useful for professional work
- 😞 Inaccurate electrical simulation
- 😞 App is broken/crashes

**Reported bugs**

- App crashes on launch
- App doesn't work after download
- Blank white screen on opening
- App won't open, only shows a folder
- Lights won't turn on

**Requested features**

- Add more components (diodes, transistors, capacitors, inductors, speakers, microphones, resistors, switches, LEDs, displays, transformers)
- Add labels/names for components
- Add intensity and voltage for cables
- Add undo/redo buttons
- Add tutorials or guidance videos


## Frequently asked questions

### Is Four free?

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

### Is Circuitry free?

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

### Which has better reviews, Four or Circuitry?

Four is rated higher. Four averages 4.7 out of 5 from 89 ratings, while Circuitry averages 3.9 from 156 ratings.

### Do Four or Circuitry have ads?

Neither Four nor Circuitry shows ads.

### Which is updated more often, Four or Circuitry?

Four ships an update every 7 months, and Circuitry every 4 months. Most recently, Four was updated on October 15, 2026 and Circuitry on October 21, 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.*