DigicalSim (formerly: iLogicDesigner) is a full featured app which assists students in logic design, digital engineering, computer science and mathematics.
The app based on basic digital building blocks, logic gates. No knowledge of logic gates or digital circuits is required.
It offers the basic building blocks, wiring tools and a flexible plane to create live real-time digital circuits, ideal for anyone who wants to learn the basic principles of how computers work - especially students of digital engineering, learn how to create simple logic gates, latches, flip-flops, adders, shift registers and counters. it can help them perform complete lab experiments.

► Features:
- AND, NAND, OR, NOR, XOR, XNOR, Buffer, NOT, J-K Flip-Flop, D Flip-Flop, T Flip-Flop, Switch, Clock, Vcc, GND, VLink-Out, VLink-In, LED, 7-Segment Hex Display, 8-LED Stack Bar, Buzzer, and Label.
- Flood gates (3 & 4) inputs for the gates (AND, NAND, OR, NOR, XOR, XNOR).
- Optional Tri-State pin for the gates (Buffer, NOT), with Pull-up & Pull-down.
- Optional Clock pin for J-K Flip-Flop.
- Optional Clear pin for D and T Flip-Flops.
- Multi-Color smooth curved wires.
- Ability to add Virtual Links for tidy circuits.
- Unlimited scrollable plane space, for extra large projects.
- Run mode for clean circuit look, while operating live.
- Circuit Lock, for safe Run.
- Two switch operation modes (Toggle or Pulse).
- Switchable synchronized digital waveform clock generators. with adjustable frequency.
- Switches can be linked to work exclusively together.
- Both Positive edge & Negative edge triggering supported for flip-flops, with indicator.
- Configurable LED light color.
- Live value indicators at each leg, for easy analysis.
- Customizable tag for elements.
- Customizable labels can be added anywhere.
- Design-Time snap grid for easier alignment and cleaner look.
- Zoom in & out, Also can be automatically zoomed to Show Circuit extents.
- Persistent Circuit, it saves current circuit automatically to be completed later.
- Save and load circuits using file manager.
- A library of ready made circuit examples for quick jump start.
- Circuits Can be shared and printed.
- Re-assignable circuit diagram origin.
- Append another circuit to the current circuit.
- Highlight the gate wirings while dragged.
- Select, deselect, duplicate, move & delete gates in groups.
- Groups of elements can have distinctive Color and Label with customizable font and font color.
- Auto scroll the plane when reach the edged while wiring, dragging or selecting.
- Elastic selection rectangle to easily select elements.
- Undo functionality, with 10 steps backward.
- Direct wiring to use with Apple Pen.
- Support to Pick'n Drop.
- Boolean function viewer for each Gates & LED, while in run mode.
- Live Timeline Viewer.

What’s New

Version 4.5

- Added Tri-State Buffer with pull-up & pull-down.
- Added Tri-State NOT Gate with pull-up & pull-down.
- Added Buzzer with independent serial.
- Added independent serial for LEDs.
- Added Hex Digit Display (it was BCD).
- Added optional Clock input for the J-K Flip-Flop.
- Added optional Clear input for both the D and T Flip-Flops.
- Added more Example libraries.
- More Organized menus.
- Some UI Tweaks.
- Updated App Icon.
- Updated App Info.
- iOS 13 Compatibility.
- Some fixed bugs.

Ratings and Reviews

4.8 out of 5
5 Ratings

5 Ratings

Skaguay ,

Fantastic App

This app is fantastic! I use it to demonstrate and “play” with digital logic. Much better than getting out the breadboard an my old TTL chips. Well thought out and friendly interface.



it does what it needs to in a great way.

To build an advanced circuit, an ipad helps with the additional scene space and an apple pencil helps with the tiny buttons

it's really good for what it is

question for the developer: there is a "share" option. i finished a cool circuit and i wanted to see how to export it, and the app crashes vey time i click the "share" button... what are the designed export options?


love the app

Developer Response ,

Thanks for using the App, The Share option uses the standard iOS Share sheet, which let you pick the app you want to share the design with.. The main two choices is the Mail App, and the Files App...
However, I've tested the share option in the app, and it seems to work well. If this issue is still happen, then please send the details to the Support mail address.. and Include the device model name, iOS version, App version, and a screenshot of the error message...

Patrickl27 ,

UPDATE: Great logic simulator, very responsive developer

UPDATE 2: The latest update fixes the remaining issues I had with the app 😄. I would definitely recommend this app to anyone needing a logic simulator on their phone, and the developer is very responsive to fixing any problems you find in the app, and adding any useful suggestions 😀.
One minor UI tweak that would be nice is if the zoom in/out would be centered between your fingers, like it is on most other iOS apps, rather than being centered on the top left corner as it is now. Alternatively being centered on the center of the screen when zooming would be slightly less ideal, but still better than it is now, and likely easier to implement.
It also would help when making complex circuits if when you’re interacting with a particular component, the lines coming out of it were highlighted in a different color, and similarly, when running the circuit, if the lines were highlighted showing if they were on/off, rather than just the dot at either end showing that like it is now. It would also be useful to be able to change the colors of wires after creating them, and easily change the color of all wires going to a particular connection at once.
It also could make it easier to deal with circuits if when dragging a wire to an off-screen part it would automatically scroll when pulling it to the edge of the screen, or let you scroll manually with another finger.

UPDATED REVIEW: The new update fixes most of the problems I originally noted, making this app much more friendly to use 😃. It’s great that the developer listens to and acts on user feedback. However, on the iPhone X many of the top bar’s buttons are mostly blocked by the phone’s “notch”, resulting in users needing to tap randomly in that area and memorize the position of the different functions. Once this bug is fixed I will definitely use this app often.
Overall this is a great update, with just this one pain point for some devices.

Another nice-to-have but not essential feature would be the ability to open multiple circuits at once and connect them together/combine them, which would allow modular design that could be connected when complete. A good example of its use is with the multiplexer and demultiplexer example circuits, which could be combined together to better demonstrate their function.

ORIGINAL REVIEW: This app works, but is not very user friendly. It would be much more useable if you could zoom in an out, as another review mentioned, you can barely fit any useful logic in a single screen before needing to scroll. It would also be useful to have an alternate method to long tapping, for example 3D Touch on iPhone 6s and newer. Also just decreasing the delay of the the long tap required might help quite a bit.

With these things fixed and a few other small things (e.g. a typo, the Help menu is labeled "Halp"). Also the developer should really be more kind to users, rather than accusing them of "not having common sense", instead realize that perhaps the app could communicate functionality better.

This app also freezes occasionally, requiring a force quit, losing my progress, which obviously needs fixing.

The ability to save and load projects is also critical in this sort of app.

Overall the app works, but is likely not user friendly enough for widespread regular use, but with a few minor improvements as mentioned above it could be incredibly useful! I hope the developer takes my advice in this review, this app has the potential to be great!

Developer Response ,

Thanks for rating, I just released an update, which includes most of your recommendations. plus a lot more.
Thanks & Regards.


Amran AlQasmi
39.3 MB

Requires iOS 7.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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