iCircuit

Name: iCircuit
Price: 12.99 USD
Rating: 3.8 (128 reviews)
Author: Krueger Systems, Inc.

Real-time circuit simulator

$12.99 · In‑App Purchases

128 Ratings
Ages

4+
Years
Category

Productivity
Developer

Krueger Systems, Inc.
Language

EN
+ 9 More
Size

163.8
MB

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/

Ratings & Reviews

3.8

out of 5

128 Ratings

Seems excellent, Few things missing
11/26/2020

Phosyy
First off, fantastic app. The features work well, and overall i think the UI is handled very well. The app has all the basic parts that are needed to do most of what I would want to do. I recommend this app overall. That being said, there’s some limitations i’ve noticed from playing with the app (hopefully eventually to be addressed). One: no built in non-ideal op-amps. At the very least having control/modeling some basic things like slew rate adjustments and output capabilities without using a subcircuit model would be great.Another thing missing is vacuum tubes, along with triacs and diacs. People have requested it but the author has said looking into it since 2014, without much update, at the very least copying the models from the source of Falstad’s site would work if that’s the holdup. TVS devices (both single and bidirectional) and MOVs would be nice too. Along with spark gaps. SCRs do exist already though, and fairly powerful dependent sources and subcircuit support means it’s likely possible to manually implement common models of these components somewhat, but it’s not an ideal path. A huge feature would be supporting some sort of bode plot setup, even just something basic like a series of transient analysis passes across a frequency range would go a long way if i could observe phase and gain plots. DC analysis at different varying operating conditions would be another super useful feature and probably easy to add.Finally noise analysis. The most practical and I suspect the least easy to jump on but it would have a lot of value for making the app cover all the bases of basic circuit analysis needs.The settings dialog and using the file browser interface as the home screen was a little confusing but was really not too hard to figure out and the documentation is very straightforward. The Arduino integration is very neat and makes this app one of the more useful circuit simulation references I’ve been able to design with.
Seems excellent, Few things missing
11/26/2020

Phosyy

First off, fantastic app. The features work well, and overall i think the UI is handled very well. The app has all the basic parts that are needed to do most of what I would want to do. I recommend this app overall. That being said, there’s some limitations i’ve noticed from playing with the app (hopefully eventually to be addressed). One: no built in non-ideal op-amps. At the very least having control/modeling some basic things like slew rate adjustments and output capabilities without using a subcircuit model would be great.Another thing missing is vacuum tubes, along with triacs and diacs. People have requested it but the author has said looking into it since 2014, without much update, at the very least copying the models from the source of Falstad’s site would work if that’s the holdup. TVS devices (both single and bidirectional) and MOVs would be nice too. Along with spark gaps. SCRs do exist already though, and fairly powerful dependent sources and subcircuit support means it’s likely possible to manually implement common models of these components somewhat, but it’s not an ideal path. A huge feature would be supporting some sort of bode plot setup, even just something basic like a series of transient analysis passes across a frequency range would go a long way if i could observe phase and gain plots. DC analysis at different varying operating conditions would be another super useful feature and probably easy to add.Finally noise analysis. The most practical and I suspect the least easy to jump on but it would have a lot of value for making the app cover all the bases of basic circuit analysis needs.The settings dialog and using the file browser interface as the home screen was a little confusing but was really not too hard to figure out and the documentation is very straightforward. The Arduino integration is very neat and makes this app one of the more useful circuit simulation references I’ve been able to design with.
Garbage Programming
11/21/2025

ThreePhase220
This app has issues with the smallest and simplest things like laying wires and connections. Super buggy. Want to edit an unused connection by adding a wire? Simple right? Nope. Click the connection point and drag like it asks? Not a chance. “Don’t worry though”, you can add a random line in the middle of nowhere and build off that instead. It’s honestly laughable. Want to Rotate? We’ll make it extremely hard for you so you have to tap, wait, tap again for the menu, then scroll through the 10 options until you get to the end where the most useful feature is. Make a button!!!!! Honestly it’s crazy how badly this app is managed from a mobile stance. Don’t even get me started on the “Undo” feature. Did you spend a few minutes making a solid effort to complete your design and make a small mistake? No problem, the Undo feature will erase all of that in one button press. :) didn’t want to do all that? Dang that’s crazy, we didn’t make an option for you to Redo to get your work back. At this point I uninstalled and won’t be back again. Having a Pro option is wild before finalizing the Standard version. Good luck :)
Garbage Programming
11/21/2025

ThreePhase220

This app has issues with the smallest and simplest things like laying wires and connections. Super buggy. Want to edit an unused connection by adding a wire? Simple right? Nope. Click the connection point and drag like it asks? Not a chance. “Don’t worry though”, you can add a random line in the middle of nowhere and build off that instead. It’s honestly laughable. Want to Rotate? We’ll make it extremely hard for you so you have to tap, wait, tap again for the menu, then scroll through the 10 options until you get to the end where the most useful feature is. Make a button!!!!! Honestly it’s crazy how badly this app is managed from a mobile stance. Don’t even get me started on the “Undo” feature. Did you spend a few minutes making a solid effort to complete your design and make a small mistake? No problem, the Undo feature will erase all of that in one button press. :) didn’t want to do all that? Dang that’s crazy, we didn’t make an option for you to Redo to get your work back. At this point I uninstalled and won’t be back again. Having a Pro option is wild before finalizing the Standard version. Good luck :)
Sounded fun, but it’s a nightmare.
03/02/2021

AppleKingOfTerribleUX
I really wanted to play around with a simulation, but it fights you every step of the way. The settings are barebones, the interface, drawing and deleting fight you EVERY step of the way, you can’t rotate stuff and scaling things is only in one direction, for a barebones list of components they just direct you to the wiki instead of detailing the twenty or so in-app for QoL. This would be a fun $2-5 toy to play around making basic starter boards, but I’d be laughed out of an office if I handed the spaghetti mess that comes out of this to a professional. Eh, at least it was an entertaining thirty minutes for an extreme premium.Oh yeah, and hats off to the inept technical genius who made it so pressing “undo” keeps undoing thirty minutes of stuff. This UI is a technical dumpster fire.I’m going to RTFM and give it one last shot later, but that won’t fix the lack of intuitive and intelligent design.
Sounded fun, but it’s a nightmare.
03/02/2021

AppleKingOfTerribleUX

I really wanted to play around with a simulation, but it fights you every step of the way. The settings are barebones, the interface, drawing and deleting fight you EVERY step of the way, you can’t rotate stuff and scaling things is only in one direction, for a barebones list of components they just direct you to the wiki instead of detailing the twenty or so in-app for QoL. This would be a fun $2-5 toy to play around making basic starter boards, but I’d be laughed out of an office if I handed the spaghetti mess that comes out of this to a professional. Eh, at least it was an entertaining thirty minutes for an extreme premium.Oh yeah, and hats off to the inept technical genius who made it so pressing “undo” keeps undoing thirty minutes of stuff. This UI is a technical dumpster fire.I’m going to RTFM and give it one last shot later, but that won’t fix the lack of intuitive and intelligent design.
I heart this app
10/14/2023

Who Cares about nicknames9
I am no electrician, but I love to tinker. I know enough to be “the one in the family/group” to go to.I last used this app to help me create a simple LED driver for an array of grow lamps of different frequency and intensity with potentiometers (I love to over do my projects with options). Some plants like full sun, some don’t. Some respond better to more ultraviolet, some other frequencies.Now, go online and find a decent set of grow lamps with the same features and watch your wallet disappear. Always DIY when you can. This app can help with such things!
I heart this app
10/14/2023

Who Cares about nicknames9

I am no electrician, but I love to tinker. I know enough to be “the one in the family/group” to go to.I last used this app to help me create a simple LED driver for an array of grow lamps of different frequency and intensity with potentiometers (I love to over do my projects with options). Some plants like full sun, some don’t. Some respond better to more ultraviolet, some other frequencies.Now, go online and find a decent set of grow lamps with the same features and watch your wallet disappear. Always DIY when you can. This app can help with such things!

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.