# iCircuit — Real-time circuit simulator

> Real-time electronic circuit design and simulation app with extensive component library. (iPhone/iPad app by Krueger Systems, Inc..)

- Source: https://appshunter.io/ios/app/icircuit/id383359044 (this page in markdown: same URL + `.md`)
- Developer: [Krueger Systems, Inc.](https://appshunter.io/developer/299293363)
- Category: Productivity, Education
- Price: $12.99 with in-app purchases
- Rating: 3.80/5 from 134 App Store ratings · 682 written reviews indexed
- Age rating: 4+
- Requires: iOS 12.2 · 126 MB
- Languages: American English, French (France), German (Germany), Italian, Japanese, European Portuguese, Russian, Chinese (Simplified, China), European Spanish, Chinese (Traditional, Taiwan)
- Released: 2010-07-29
- Data updated: 2026-08-27
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/icircuit/id383359044/reviews.md

## What is iCircuit?

iCircuit is the premier iPhone and iPad app for designing, simulating, and learning analog and digital electronics. Its advanced simulation engine provides real-time, always-on analysis so your circuits stay powered and live, just like working with real components.

Use it like a CAD tool: add components, wire them up, and set their properties. But iCircuit is unlike typical CAD apps because it is always simulating. You do not stop to take a measurement or spend time configuring reports. Instead, you just play with the circuit as you normally would, with the power on.

Build circuits with over 300 components, from simple resistors and LEDs to programmable Arduinos (Uno, Nano, Mega, ESP8266, ESP32), PIC microcontrollers, and 60 4000/7400-series digital ICs (more available with Pro). Connect elements, adjust values, and instantly see the results.

BUILT-IN TEST EQUIPMENT  
• Multimeter: Probe any point to read voltage, current, and power  
• Oscilloscope: Track multiple signals with touch-controlled time scale, stacked/unstacked views, FFT analysis, and Bode plots  
• Gauges: Visualize voltages, currents, and frequencies directly in your circuit  
• Signal generators and configurable sources  

EXTENSIVE COMPONENT LIBRARY  
• Programmable Arduinos (Uno, Nano, Mega, ESP8266, ESP32)  
• Programmable PIC microcontrollers (assembly and HEX files, more available with Pro)  
• Power: Voltage regulators (78xx, LM317), sources, dependent sources, power jacks, and simulated antennas  
• Analog: Resistors, capacitors, inductors, diodes, BJTs, MOSFETs, thermistors, triodes, and tetrodes  
• Digital: Logic gates (AND, OR, NAND, NOR, XOR), JK and D flip-flops, and 60 4000/7400-series ICs (180+ available with Pro) 
• ADCs and DACs  
• Sensors and displays: LEDs, 7-segment, NeoPixels, matrix displays, thermistors  
• Electromechanical: Motors, servos, SPST/SPDT and DPST/DPDT switches, push buttons, relays, and speakers  

CREATE CUSTOM ELEMENTS
Build sub-circuits and custom elements to componentize your designs and create reusable modules. Share your custom elements with others via the iCircuit Gallery.

AUDIO SIMULATION
Hear your circuits. Speakers, buzzers, and microphones produce real audio output.

Perfect for students learning electronics, hobbyists prototyping projects, and engineers validating designs, all without burning out a single component.

ABOUT ICIRCUIT PRO (OPTIONAL)
iCircuit is a complete app with a one-time purchase. iCircuit Pro is optional and adds extra components (including more PICs and a larger 4000/7400 IC library) and helps fund ongoing development. Pro is not required for core simulation or everyday circuit design.

Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

## Key features

- Real-time circuit simulation
- Extensive component library (300+)
- Built-in test equipment (multimeter, oscilloscope)
- Programmable Arduino and PIC microcontroller support
- Custom element creation and sharing
- Audio simulation

## Pricing and in-app purchases

Base price: $12.99.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| iCircuit Pro (Monthly) | $1.99 | per month |
| iCircuit Pro (Yearly) | $14.99 | per year |


## Chart rankings

- #184 in Top Paid · Productivity (US App Store)

## What do users think of iCircuit?

Overall sentiment: neutral

**Pros**

- 🚀 Great for learning and testing
- 👍 Intuitive and easy to use
- 💡 Programmable Arduino integration
- 👍 Useful for hobbyists and students

**Cons**

- 🐛 Buggy and crashes frequently
- 🔧 Difficult to edit and delete components
- 🔧 Limited component library
- 🔧 Inaccurate simulation results in some cases

**Commonly reported bugs**

- Oscilloscope and meter functions not working properly
- Saving and loading circuits can be unreliable
- Inconsistent behavior when rotating/flipping components
- Crashes when working with larger or more complex circuits

**Most requested features**

- More components (e.g. transformers, triodes, MOSFETs)
- Ability to create custom components
- Frequency domain analysis (Bode plots, FFT)
- Improved wiring and component placement controls
- Better support for AC circuits and motors

## Recent user reviews (10 of 682)

All indexed reviews: https://appshunter.io/ios/app/icircuit/id383359044/reviews.md

### 2/5 — Almost great

*2026-05-10, version 1.15.2*

I would pay for the pro. But honestly, even the small list of components isn’t worth it. It’s missing so much. 

Paying monthly/annually isn’t worth the money. I want to see prolong degradation of circuits and overheating. I want to know if my design will fail. 

So much potential but not worth paying for.

### 5/5 — Great App for electrical and electronic circuit simulation

*2026-05-05, version 1.15.2*

I have tried several apps for circuit simulation, but iCircuit is the best among them. Thank you to the developer for providing such a fantastic app.

### 1/5 — Select by lasso bug

*2026-03-12, version 1.15*

I am leaving this 1 until you fix your lasso selection bug. It’s impossible to highlight certain components

### 5/5 — Amazing application

*2026-03-04, version 1.15*

Best app in App Store for an EE. From a licensed engineer with a masters in electrical engineering. Super well built, easy to prototype on the go.

Developer has my Respect.

### 1/5 — Pagar de nuevo?

*2026-02-28, version 1.15*

Borrando y usando chat gpt!

### 5/5 — Excellent

*2026-02-15, version 1.14.2*

I wait n wait for that other company very big ? Never have they seen a mac NOR an iPhone … but hey iCircuit has been on my list , i will never ever be able to thank you enough,

### 1/5 — sad

*2025-12-30, version 1.14.2*

This app deserves more negative reviews. It's super-amateur and riddled with bugs/annoyances.

I wanted to use this to sketch circuits on an iPad. It's not good for that because the components are so buggy and limited.

The UI doesn't work the way you would expect. You can't place things like you would expect. Basic functions like zooming and moving the canvas just don't work right. Snapping is frustrating and inconsistent. Sometimes when you tap an item it brings up one menu, sometimes it brings up a different menu. When using the app the canvas often gets stuck where you can't scroll down to see the bottom half of what you're working on, and the only way to fix it is to close the project and open it again.

The pencil doesn't work right. It gets stuck doing nothing on a lot of taps. It kinda works sometimes, but the app was definitely not tested with the pencil. It's made to work with your finger.

Scrolling lists of components is frustrating because there's no scrollbar and no room between components to 'grab' the list and scroll it. Most of the time you try to scroll a list it will think you're trying to drag the component out of the list and place it.

Labelling things is not something the developer wants you to do. Components have a name you can edit, but many don't actually display the name. Traces/nets can't have names. There is a 'text label' component, but if you try to use it you'll realize there is an invisible barrier preventing you from actually placing it near other things. So you can't make an adjacent label, and you certainly can't place a label on top of something.

Take a basic component — the TRS jack. It doesn't show the name you give it, and it doesn't have labels for tip/ring/GND. By default it's facing right. If you want to make it face left, you can only rotate it 180º so now it's upside down with GND on top and tip on the bottom which is confusing because you can't label things. There's a 'flip' option but it doesn't actually flip the component. It just roates it 180º. So it just does the exact same thing as rotating it twice. That's not very useful unless you like upside-down jacks with unnamed leads coming out of them. You're better off using 'internal port' for anything you want a name on.

There's no consistancy. The TRS jack rotates and flips, but 'flip' actually rotates instead of flipping. But if you want to rotate an IC there is no 'rotate' option, there's just 'flip', and in this case it actually DOES flip the IC to a mirror image. That's not something you'd EVER want (unless you're drawing a circuit where the IC is on the bottom side of the PCB and you're looking through it from the top).

Point being nothing works the way you want it to. If you want to sketch a circuit you're better off sketching it in a basic drawing app or sketching it on a piece of paper and taking a picture. This app won't improve your workflow.

Most of the problems are things a developer with mobile experience could fix in an afternoon, but this developer is still charging $12.99 yet is unwilling/unable to fix any of the UI for 10+ years.

### 1/5 — Don’t buy, bought full app, year later they remove features for subscription

*2025-12-29, version 1.14.2*

Bought this app full price a year or two ago for full price. Get on today to find out a lot of my components are unable to use unless I sign up for the subscription.. like everything else in this world. Scam don’t download or use

### 1/5 — 日本語対応していない

*2025-12-22, version 1.14.2*

textlabelに日本語を入力すると文字化けしてしまい非常に使いにくい

### 1/5 — Fehlerhaft

*2025-12-08, version 1.14.2*

Ich habe in einem ganz simplen Schaltkreis eine ganz simple LED mit einem Transistor betreiben wollen. 2 Stunden lang quälte ich mich mit den Anzeigen, die nicht mit dem gezeigten übereinstimmten. Auch wenn die Basisstrecke keinerlei Strom führt, fließt fleißig und viel Strom über die LED. Das kann physikalisch nicht sein. Da ist ein Hoax drin. So ist das Programm für mich unbrauchbar.

Ich bitte um Rückerstattung der Kaufsumme ..

## Frequently asked questions about iCircuit

### What does iCircuit do?

iCircuit is an application for designing and simulating analog and digital electronic circuits in real-time. It allows users to build circuits with a vast array of components, connect them, adjust properties, and instantly see the results of their designs.

### What are the key features of iCircuit?

Key features include a real-time simulation engine, over 300 components in its library (including Arduinos and microcontrollers), built-in test equipment like a multimeter and oscilloscope, the ability to create and share custom elements, and audio simulation capabilities.

### Is iCircuit free to use?

iCircuit is a paid application with a one-time purchase. While there is an optional 'iCircuit Pro' for additional components, the core simulation and everyday circuit design functionalities are available with the initial purchase.

### What devices is iCircuit compatible with?

The application is designed for iPhone and iPad devices, leveraging their touch interfaces for intuitive circuit design and manipulation.

### Who would benefit from using iCircuit?

This app is perfect for students who are learning about electronics, hobbyists who are prototyping their own projects, and engineers who need to validate their designs before building them physically, all without the risk of damaging components.

## Version history (last 5 releases)

### 1.15.2 — 2026-03-18

This small update fixes signing into the iCircuit Gallery to upload custom elements and fixes the link to the iCircuit Manual.

1.15.1: Fixes the lasso selection tool, fixes crashes on iOS 12 devices, fixes thumbnail generation, and it fixes the D12 port label on Arduino Nanos

# Version 1.5 Updates

This major update brings powerful new analysis tools, expanded microcontroller support, and numerous improvements.

## Bode Plot Analysis

Unlock frequency response analysis with new Bode plot capabilities! Visualize how your circuits respond across frequencies with magnitude and phase plots. Perfect for analyzing filters, amplifiers, and frequency-dependent circuits. See cutoff frequencies, gain characteristics, and phase relationships at a glance.

## Expanded Microcontroller Support

- **Arduino Mega** - Build bigger projects with 54 digital I/O pins and 16 analog inputs
- **Arduino Nano** - Compact board ideal for small-scale applications
- **ESP32 and ESP8266** - Enhanced support for popular IoT microcontrollers

## New Circuit Elements

- **AC Motor** - Single phase AC induction motor
- **Barrel Connector** - Professional DC power jack for your circuits with configurable shunt terminal
- **Improved Power Supply Jack** with better connection handling

## Quick Search

Find circuit elements faster than ever! New search bar lets you instantly locate components without scrolling through categories. Just start typing and get to building.

## Voltage Monitoring

Protect your circuits with automatic under-voltage and over-voltage warnings. Get notified when components are operating outside their safe voltage ranges, helping prevent damage to sensitive ICs and ensuring reliable operation.

## Element Library Organization
- New Microcontroller category for better organization
- Improved element filtering options
- Elements sorted by Pro availability for easier discovery

## Bug Fixes

- Fixed photodiode and photoresistor light source selection
- Removed false capacitor loop errors that prevented valid circuits from running
- Added input voltage tolerance for digital ICs to prevent spurious warnings from minor voltage fluctuations
- Better handling of Arduino EEPROM and multiple board types

Thank you for your continued support! Whether you're learning electronics, prototyping professional designs, or just having fun building circuits, we hope v1.15 makes your experience even better.

### 1.15.1 — 2026-03-16

This small update fixes the lasso selection tool, fixes crashes on iOS 12 devices, fixes thumbnail generation, and it fixes the D12 port label on Arduino Nanos

# Version 1.5 Updates

This major update brings powerful new analysis tools, expanded microcontroller support, and numerous improvements.

## Bode Plot Analysis

Unlock frequency response analysis with new Bode plot capabilities! Visualize how your circuits respond across frequencies with magnitude and phase plots. Perfect for analyzing filters, amplifiers, and frequency-dependent circuits. See cutoff frequencies, gain characteristics, and phase relationships at a glance.

## Expanded Microcontroller Support

- **Arduino Mega** - Build bigger projects with 54 digital I/O pins and 16 analog inputs
- **Arduino Nano** - Compact board ideal for small-scale applications
- **ESP32 and ESP8266** - Enhanced support for popular IoT microcontrollers

## New Circuit Elements

- **AC Motor** - Single phase AC induction motor
- **Barrel Connector** - Professional DC power jack for your circuits with configurable shunt terminal
- **Improved Power Supply Jack** with better connection handling

## Quick Search

Find circuit elements faster than ever! New search bar lets you instantly locate components without scrolling through categories. Just start typing and get to building.

## Voltage Monitoring

Protect your circuits with automatic under-voltage and over-voltage warnings. Get notified when components are operating outside their safe voltage ranges, helping prevent damage to sensitive ICs and ensuring reliable operation.

## Element Library Organization
- New Microcontroller category for better organization
- Improved element filtering options
- Elements sorted by Pro availability for easier discovery

## Bug Fixes

- Fixed photodiode and photoresistor light source selection
- Removed false capacitor loop errors that prevented valid circuits from running
- Added input voltage tolerance for digital ICs to prevent spurious warnings from minor voltage fluctuations
- Better handling of Arduino EEPROM and multiple board types

Thank you for your continued support! Whether you're learning electronics, prototyping professional designs, or just having fun building circuits, we hope v1.15 makes your experience even better.

### 1.15 — 2026-02-28

This major update brings powerful new analysis tools, expanded microcontroller support, and numerous improvements.

## Bode Plot Analysis

Unlock frequency response analysis with new Bode plot capabilities! Visualize how your circuits respond across frequencies with magnitude and phase plots. Perfect for analyzing filters, amplifiers, and frequency-dependent circuits. See cutoff frequencies, gain characteristics, and phase relationships at a glance.

## Expanded Microcontroller Support

- **Arduino Mega** - Build bigger projects with 54 digital I/O pins and 16 analog inputs
- **Arduino Nano** - Compact board ideal for small-scale applications
- **ESP32 and ESP8266** - Enhanced support for popular IoT microcontrollers

## New Circuit Elements

- **AC Motor** - Single phase AC induction motor
- **Barrel Connector** - Professional DC power jack for your circuits with configurable shunt terminal
- **Improved Power Supply Jack** with better connection handling

## Quick Search

Find circuit elements faster than ever! New search bar lets you instantly locate components without scrolling through categories. Just start typing and get to building.

## Voltage Monitoring

Protect your circuits with automatic under-voltage and over-voltage warnings. Get notified when components are operating outside their safe voltage ranges, helping prevent damage to sensitive ICs and ensuring reliable operation.

## Element Library Organization
- New Microcontroller category for better organization
- Improved element filtering options
- Elements sorted by Pro availability for easier discovery

## Bug Fixes

- Fixed photodiode and photoresistor light source selection
- Removed false capacitor loop errors that prevented valid circuits from running
- Added input voltage tolerance for digital ICs to prevent spurious warnings from minor voltage fluctuations
- Better handling of Arduino EEPROM and multiple board types

Thank you for your continued support! Whether you're learning electronics, prototyping professional designs, or just having fun building circuits, we hope v1.15 makes your experience even better.

### 1.14.2 — 2025-04-23

1.14.2 Fixes crashes when WiFi is disabled

Here are the 1.14 release notes:

Improved element and wire selection.

New elements:
* RGB Led
* 74HC4551 Analog Multiplexer and Demultiplexer
* Custom Element

New capabilities:
* Added the capability to create Custom Elements in an Arduino like way
* Added the capability to add resistors, inductors and capacitors to the Custom Elements
* Added the capability to use SPI bus with Custom elements
* Added the capability to draw shapes over the chip and create animations using the drawing functions in the Custom Elements
* Added the capability to save persistan data through an EEPROM with the Custom Elements
* Added the capability of login to the Gallery directly into the application
* Upload Custom Elements to the Gallery directly from the application
* Create and upload Custom Element revisions directly to the Gallery
* Pull Custom Element revisions from the Gallery directly into the application

Custom Elements:


Fixes:
* SPI disconnections when a modification
* I2C disconnections when a modification

### 1.14.1 — 2025-04-12

1.14.1 Fixes parallel capacitors.

Here are the 1.14 release notes:

Improved element and wire selection.

New elements:
* RGB Led
* 74HC4551 Analog Multiplexer and Demultiplexer
* Custom Element

New capabilities:
* Added the capability to create Custom Elements in an Arduino like way
* Added the capability to add resistors, inductors and capacitors to the Custom Elements
* Added the capability to use SPI bus with Custom elements
* Added the capability to draw shapes over the chip and create animations using the drawing functions in the Custom Elements
* Added the capability to save persistan data through an EEPROM with the Custom Elements
* Added the capability of login to the Gallery directly into the application
* Upload Custom Elements to the Gallery directly from the application
* Create and upload Custom Element revisions directly to the Gallery
* Pull Custom Element revisions from the Gallery directly into the application

Custom Elements:


Fixes:
* SPI disconnections when a modification
* I2C disconnections when a modification

## Apps similar to iCircuit

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [EE ToolKit PRO for iPad](https://appshunter.io/ios/app/ee-toolkit-pro-for-ipad/id393145367) | 4.8 (79) | $8.99 | Productivity |
| [Electronics Engineer Helper](https://appshunter.io/ios/app/electronics-engineer-helper/id896429646) | 4.8 (432) | Free | Productivity |
| [EE ToolKit PRO](https://appshunter.io/ios/app/ee-toolkit-pro/id368780426) | 4.9 (293) | $12.99 | Productivity |
| [Calctronics: Circuit Calc](https://appshunter.io/ios/app/calctronics-circuit-calc/id1583972990) | 4.0 (5) | Free | Productivity |
| [System Designer](https://appshunter.io/ios/app/system-designer/id1132983280) | 4.4 (17) | Free | Productivity |
| [CircuitShepherd](https://appshunter.io/ios/app/circuitshepherd/id1598606653) | 1.5 (2) | Free | Productivity |

## More apps by Krueger Systems, Inc.

- [Live Spectrogram](https://appshunter.io/ios/app/live-spectrogram/id630831185)
- [Math Agility](https://appshunter.io/ios/app/math-agility/id632744606)
- [Calca](https://appshunter.io/ios/app/calca/id635757879)
- [Mocast](https://appshunter.io/ios/app/mocast/id897185985)
- [Continuous .NET C# and F# IDE](https://appshunter.io/ios/app/continuous-net-c-and-f-ide/id1095213378)

All apps by Krueger Systems, Inc.: https://appshunter.io/developer/299293363

## Related topics

[icircuit](https://appshunter.io/ios/topics/icircuit) · [icircuit 3d](https://appshunter.io/ios/topics/icircuit-3d) · [circuit simulator q](https://appshunter.io/ios/topics/circuit-simulator-q) · [circuit simulator electronic](https://appshunter.io/ios/topics/circuit-simulator-electronic) · [operational amplifiers guide](https://appshunter.io/ios/topics/operational-amplifiers-guide)

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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 2026-08-27.*