DigicalSim (formerly: LogicDesigner) 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 Display, LED Stack Bar, and Label.
- Flood gates (3 & 4) inputs for the gates (AND, NAND, OR, NOR, XOR, XNOR).
- 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.
- Selection / Pan tool.
- Live Timeline viewer with Play/Pause/Step Forward.
- Probe icon on each Gate chosen to be monitored.
- Boolean function Viewer for all Gates and Flip-Flops.

What’s New

Version 4.2

- Hotfix Timeline when recursive wiring is used.

Ratings and Reviews

EMC_5987 ,

Easy to use

It’s easy & fast to add elements, and it’s a nice implementation (especially for students, as you can hit the ground running instead of taking a couple days just to learn the design tool). It might be missing some of the components a professional would use, but it’s got enough for most students & DIYers.

The only thing I found unintuitive was adding wires. You need to click and hold your component for a few seconds. There are multiple options for wire colors, which is nice since you can tell at a quick glance which inputs go where, but some of the colors aren’t clickable.

Developer Response ,

I just updated the app, wiring now is easier, and colors are now clickable, it was working well on system scale 100%, but some of the colors became un-clickable when the system scale is more than 100%. this issue now is fixed. and now it is working in any scale.
Also i've added tons of new features, please update your app, and re-rate accordingly.

Salloy ,

2.4 Update

With this update the Flip Flops have been fixed on the negitive edge. the Positive edge sill has the same problems. When first flip flop gets a signel all the flips flops in a shift register will change.

Developer Response ,

Thank you for your comments, it is now updated, fixed your valid point, added tons of new features, aligned with iOS version. Please update your app and re-rate accordingly.


Amran AlQasmi
6.5 MB

OS X 10.6.6 or later

Age Rating
Rated 4+
© 2015~2018,


  • Family Sharing

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

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