Comparison

Trans4motor vs Circuitry

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Trans4motor

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
Read full description

Trans4motor is a simulator where you can control the movements of single cylinder to 12 cylinder 4 stroke engines on the iPad/iPhone. Recommended to anyone interested in car and motorcycle engines. This is for those who have a relentless love for engines and want to enhance their knowledge. #3 Top Paid iPad App in Japan #5 Top Paid iPhone App in Japan https://www.youtube.com/user/Trans4motor https://www.facebook.com/Trans4motor Features 1) Seamlessly transforms into different type of engines Select from inline to V-type, or other multi-cylinder engines, and watch the running engines transform over continuous CG animation. Enjoy watching the inline engine camshaft separate into two parts as it transforms into the V-type engine and how phase angle modulation between cylinders makes the crankshaft rotate, separate, and combine into many engine formations. 2) Add Engine Sound (In-App Purchase) Developed in technical collaboration with "CAI MEDIA CO.,LTD.", the developer of the iPhone app featuring innovative synthetic engine sound, "RealEngineSim" this new feature will add a variety of realistic engine sounds ranging from different number of cylinders to explosions with unequal intervals and cylinder rest. Engine Sound Add-On is available via In-App Purchase. 3) Accelerator Control Accelerator control is available during engine sound replay. Tilt iPhone to different degrees as if pressing the accelerator pedal. Tilt forward horizontally (as if pressing the accelerator) to activate the accelerator, and erect vertically (as if releasing the accelerator) to deactivate it. Furthermore, you can race the engine by tapping the center of rev counter. 4) Addition/expansion of engines There are currently 22 types of engines registered. Through automatic network updates, continuous expansion is planned. In addition, there are functions installed that allow users to newly register and edit engines. Able to adjust setting for engine bore stroke, firing order, and ignition timing. Easily replicate on the iPad, engines with unequal combustion intervals for two-wheelers, Inline-four crossplane or V5. 5) Interactive Movie ·Four-stroke engines ·Firing Order ·V Angle Recorded 3 controllable presentation videos. The company and product names used within the application are generally registered trademarks or trademarks of the respective companies. The objective of this application is to upload engine specifications disclosed to the public and to learn about general information regarding engines. It does not accurately replicate actual machine measurements and designs. The CG animated engine rotates at one tenth of the actual speed to enable users to learn the structure and to enjoy the visual.

About

Circuitry

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
Read full description

Welcome to Circuitry - the world's first and only 3D circuit builder! INSANELY FAST Circuitry uses an optimized, GPU-accelerated network analysis algorithm that will blow your mind. It can calculate the voltages and currents of even the largest circuits in the blink of an eye - an insanely fast blinking eye! SUPER DUPER EASY TO USE While most circuit simulators are stuck in the stone age when it comes to usability, Circuitry takes you on a time-travel journey to the future. Its' 3D interface and intuitive controls will instantly feel familiar - no lengthy tutorials required. DOCUMENT-BASED Every circuit you build in Circuitry is a file. That way, they integrate perfectly into your existing files and can be used exactly the same way: you can duplicate and modify them, share them, and they are available to you on all your devices. HOW TO USE: 1. Place components by dragging from the toolkit to the canvas. 2. Connect components by tapping the sides of the components in cabling mode. 3. Delete or modify components by long pressing on them. AVAILABLE COMPONENTS: - Resistor - Voltage source - Light bulb

Screenshots

Trans4motor4 screens
Circuitry4 screens

Verdict

The call

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.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

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.

Scorecard4 real differences · 6 level
Trans4motor versus Circuitry: the parameters behind the verdict, then further details
ParameterTrans4motorCircuitry
Price$2.99Free — better
Rating3.7 (70 ratings)3.9 (155 ratings) — better
Positive reviews56.6% of reviews — better51.4% of reviews
Number of ratings70155 — better
Update frequencyEvery 2 months — betterEvery 4 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.012.0 — better
Further details — not scored
Size24 MB35 MB
Age rating4+4+
DeveloperKitt Peak, Inc.Raffael Kaehn

Customer experience

Trans4motor

All ratings70 ratings
Positive68.6%
Neutral5.7%
Negative25.7%
Written reviews113 reviews
Positive56.6%
Neutral14.2%
Negative29.2%

Circuitry

All ratings155 ratings
Positive68.4%
Neutral12.9%
Negative18.7%
Written reviews37 reviews
Positive51.4%
Neutral13.5%
Negative35.1%

Bugs and requests

Trans4motor

Not enough reviews yet to summarise bugs or requests.

Circuitry

Reported bugs

6 issues
  • 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
Show 1 more
  • Cannot close circuits properly

Requested features

14 requests
  • 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
Show 9 more
  • Allow moving placed components
  • Add polarity for components
  • Add graphical representation of current flow
  • Add export of 2D schematic
  • Support DC and AC circuits
  • Allow use of virtual meters
  • Add oscilloscope function (graph vs time)
  • Improve UI intuitiveness
  • Add sample circuits

In-app purchases

1 purchases

Trans4motor

One-time1
  • Add Engine Sound$1.99
None

Circuitry

No in-app purchases

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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