# Trans4motor vs Circuitry

The clearest difference is price: Circuitry at Free against Trans4motor's $2.99. Circuitry also leads on in-app purchases (none vs 1) and iOS requirement (12.0 vs 15.0). On rating, review sentiment, ratings volume and update cadence there is nothing between them.

Circuitry is free to download; Trans4motor costs $2.99 up front. Trans4motor sells 1 one-off in-app purchase. Circuitry asks for nothing beyond the download.

Circuitry holds the better App Store score, 3.9 against 3.7. Both are backed by a comparable volume of ratings — 70 and 155 respectively. Written reviews complicate that: 57% of Trans4motor's written reviews are positive against 51% of Circuitry's, so the app with the better star average is not the one people write more warmly about.

Trans4motor ships an update every 2 months, Circuitry every 4 months. The most recent releases landed on September 21, 2026 and September 25, 2026 respectively.

## The numbers

| Metric | Trans4motor | Circuitry |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | [3.7 (70 ratings)](https://appshunter.io/ios/app/trans4motor-engine-simulator/id899277186/reviews) | **[3.9 (155 ratings)](https://appshunter.io/ios/app/circuitry-3d-circuit-builder/id1476733898/reviews)** |
| Number of ratings | 70 | **155** |
| Positive reviews | **56.6% of reviews** | 51.4% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 4 months |
| Monetization | Free with in-app purchases | **Free** |
| Size | 24 MB | 35 MB |
| Requires iOS | 15.0 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Kitt Peak, Inc.](https://appshunter.io/developer/399507326) | [Raffael Kaehn](https://appshunter.io/developer/1234032836) |

## What reviewers say

### Trans4motor

[App page](https://appshunter.io/ios/app/trans4motor-engine-simulator/id899277186)

Explore the mechanics of 4-stroke engines with this interactive simulator. Visualize the transformation of various engine types and understand their internal workings through detailed CG animation. Enhance your knowledge with adjustable settings and realistic engine sound options.

**Highlights:** Multi-cylinder engine transformation, Realistic engine sound (in-app purchase), Accelerator control simulation, Expandable engine library, Custom engine registration and editing, Interactive educational videos

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Add Engine Sound | $1.99 | one-time |


### 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 Trans4motor free?

Trans4motor costs $2.99, and also offers in-app purchases.

### Is Circuitry free?

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

### Which has better reviews, Trans4motor or Circuitry?

Circuitry is rated higher. Trans4motor averages 3.7 out of 5 from 70 ratings, while Circuitry averages 3.9 from 155 ratings.

### Do Trans4motor or Circuitry have ads?

Neither Trans4motor nor Circuitry shows ads.

### Which is updated more often, Trans4motor or Circuitry?

Trans4motor ships an update every 2 months, and Circuitry every 4 months. Most recently, Trans4motor was updated on September 21, 2026 and Circuitry on September 25, 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.*