# LoCAD — Logic circuits on the iPad > Digital logic circuit design and simulation software with graphical visualization. (iPhone/iPad app by Karl-Heinz Loch.) - Source: https://appshunter.io/ios/app/locad/id909593998 (this page in markdown: same URL + `.md`) - Developer: [Karl-Heinz Loch](https://appshunter.io/developer/909594001) - Category: Education, Productivity - Price: $1.99 with in-app purchases - Rating: 4.50/5 from 2 App Store ratings · 7 written reviews indexed - Age rating: 4+ - Requires: iOS 14.7 · 13 MB - Languages: American English, German (Germany) - Released: 2014-08-25 - Data updated: 2026-06-01 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/locad/id909593998/reviews.md ## What is LoCAD? LoCAD is a software for designing and simulating digital circuits. Special emphasis is given to simple creation and graphical visualization of a circuit's functioning. The inputs and outputs of the elements can be wired quite simply. Usually, two touches are sufficient. The system searches a convenient way by itself. In the simulation, you can watch the current flow and thus follow the cycle of state changes. This way, your understanding of a circuit's functioning is enhanced, and your perception of circuit faults is improved. It is possible to produce your own elements (ICs) with discretionary levels of nesting. Like this, you can build big and complex circuits in a clearly arranged way. During the simulation, you can watch the state changes in all ICs. A detailed introduction facilitates your familiarisation with the software. ## Key features - Digital circuit design - Logic simulation - Graphical visualization - Simple element wiring - Custom IC creation - State change observation ## Pricing and in-app purchases Base price: $1.99. **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | Full version | $2.99 | one-time | ## Recent user reviews (7 of 7) All indexed reviews: https://appshunter.io/ios/app/locad/id909593998/reviews.md ### 1/5 — Au weia *2025-03-04, version 8.2.1* Also irgendwie wirkt das nicht so ausgereift ### 5/5 — Excellent *2024-02-21* I am a retired physician and an electronics hobbyist. I came upon LoCAD after some success and excitement with electronic simulation programs like icircuit. I was surprised that LoCAD was not really reviewed! At first I thought that it was simply a simulator, like iCircuit. But I discovered that it was also an entire educational course that teaches Boolean electronic concepts. LoCAD is a simulator available for the Mac or iPad (apparently, it also works on Vision Pro!) in combination with two iBooks on electronic logic and microprocessors. With the LoCAD program you can teach yourself how a microprocessor works FROM THE TRANSISTOR LEVEL UP. The books show how basic digital Boolean gates are made. With the Boolean gates and their combinations (provided), you can make your own complex integrated circuits. Using the books and the program together will allow you to make a simple microprocessor with its own assembly language in short order. LoCAD LV is the free MacOS version. A maximum of 9 components can be used with this version. The LV version can be upgraded to a full version. The LoCAD SV version is the MacOS school version, which already contains the activation for the full version to enable distribution via the Apple School Manager. LoCAD and LoCAD Lite are the iOS versions that run on iPad and via Mac Catalyst on Macs. LoCAD is the full version, and in the free Lite version a maximum of 13 components can be used. My advice is to purchase the LoCad full version and the two iBooks when you start. I think people are downloading this program and not purchasing the inexpensive, well-written books which make the programming SO MUCH more understandable, unless perhaps you are already an EE chip designer. The LoCAD interface does not always adhere to the Mac interface (zooming, moving on the work area, right click menus for example), so there is a bit of a learning curve with the program interface. The iBooks on the Mac did not allow text size adjustments, perhaps because that would interfere with the interactive examples. I have not yet explored the same parts of the iBook and program on the iPad. Overall it really is an amazing introduction to electronic logic and its application. If you want to try it, purchase the two iBooks along with LoCad. With a little effort you won't be disappointed. Thank you Karl for the education! ### 1/5 — Das Geld nicht wert *2021-11-05, version 5.1.1* Schade um das Geld, App geht sofort in den Hintergrund, sobald ich etwas bearbeiten möchte und die Auswahl der Bauelemente ist rudimentär ### 4/5 — Great app but a problem *2020-11-01* I love this app! I can’t toggle the switches when the clock pulse generator is running. **Developer response:** This functionality will be enabled in version 4.2. ### 4/5 — Beste App dieser Art. *2020-07-26, version 4.1* Die App lässt Schaltkreise leicht und übersichtlich bauen und man kann gut damit lernen wie z.b. Ein Computer funktioniert oder einfach ein wenig rum probieren. Das einzige was zu bemängeln ist sind noch ab und zu abstürzte. Ein Kurzschluss Problem wurde zügig behoben und der Entwickler hat schnell auf emails geantwortet. Mittlerweile funktionieren alle Schaltungen ohne Kurzschluss. Nur 2 Schalter an einer leitung verhalten sich etwas seltsam was aber nicht wirklich schlimm ist. TL:DR : Gute App, guter Support ### 5/5 — Mehr als nur zufrieden! *2020-02-10, version 3.5* Nur ein kleines Problem: mit der Funktion „teilen“ stürzt die App ab. Mein Ziel: die einzeln gewonnenen Schaltungen auf PC sichern. Trotzdem 5 * ! ### 4/5 — Super App *2014-09-19, version 1.0.1* Super App Löschen von gespeicherten Schaltungen funktioniert nicht. Ab und zu gibt es Probleme beim abspeichern von Schaltungen. Für größere Schaltungen ist die Arbeitsfläche nicht ausreichend. Schön wäre es, wenn man selbst die Arbeitsfläche bestimmen kann. Seit dem iOS 8 Update ist die Anleitung verkehrtherum x) ## Frequently asked questions about LoCAD ### What is LoCAD? LoCAD is a software application designed for creating and simulating digital logic circuits. It focuses on making circuit design intuitive and visually clear, allowing users to easily understand how circuits function. ### How does LoCAD help in learning? LoCAD enhances understanding by providing graphical visualization of circuit operation and current flow. Users can observe state changes in real-time, which aids in grasping circuit functionality and identifying potential faults. ### Can I create complex circuits with LoCAD? Yes, LoCAD allows for the creation of custom integrated circuits (ICs) with nested levels. This feature enables the construction of large and intricate circuits in an organized manner, with state changes visible within all ICs during simulation. ### What devices is LoCAD compatible with? LoCAD is available for Mac and iPad devices. Its subtitle specifically mentions its functionality on the iPad, suggesting a strong focus on that platform. ### How much does LoCAD cost? LoCAD is a paid application, priced at $1.99. This one-time purchase grants access to the full functionality of the software. ### Is LoCAD suitable for beginners? Yes, LoCAD includes a detailed introduction to help users familiarize themselves with the software. The emphasis on simple creation and graphical visualization also makes it accessible for those new to circuit design. ### Does LoCAD have ads? No, LoCAD does not contain advertisements. As a paid application, it offers an uninterrupted user experience without any ad interruptions. ### How often is LoCAD updated? The latest version of LoCAD is 9.3, last updated on February 21, 2026. This indicates a recent update, suggesting ongoing development and support for the application. ## Version history (last 5 releases) ### 9.3 — 2026-02-21 This update fixes • the bug that prevents input and decision windows from being displayed in iOS 26 • the problem with loading and saving circuits caused by a change in iOS 26 ### 9.2 — 2026-02-17 This update fixes the bug that previously purchased full versions are not recorded correctly. ### 9.1 — 2026-02-11 This update contains stability improvements. Furthermore, the app can be tested for 7 days without any restrictions. After the trial period has expired, the app has the following restriction: • Operation cannot be activated In-app purchases that have already been made can of course be restored. ### 8.2.3 — 2025-07-07 Due to a programming error in version 8.2.2, a continuous cycle on the iPad cannot be canceled with the on/off switch. ### 8.2.2 — 2025-07-02 This update fixes minor bugs and improves performance thanks to your feedback. ## Apps similar to LoCAD | App | Rating | Price | Category | | --- | --- | --- | --- | | [ARadioaktiv](https://appshunter.io/ios/app/aradioaktiv/id6743084613) | — | Free | Education | | [Logic-Gate-Design Pro](https://appshunter.io/ios/app/logic-gate-design-pro/id1618899218) | — | $5.99 | Education | | [Bug Identifier: Buggo](https://appshunter.io/ios/app/bug-identifier-buggo/id6747819742) | — | Free | Education | | [Chip Simulator](https://appshunter.io/ios/app/chip-simulator/id1665510956) | 1.0 (7) | $0.99 | Education | | [Karel the Robot](https://appshunter.io/ios/app/karel-the-robot/id807177431) | 5.0 (1) | $1.99 | Education | | [Circuit Snap](https://appshunter.io/ios/app/circuit-snap/id6476235540) | 3.5 (2) | Free | Education | ## More apps by Karl-Heinz Loch - [LoCAD Lite](https://appshunter.io/ios/app/locad-lite/id912211392) - [Twist.It](https://appshunter.io/ios/app/twistit/id951343823) - [Card2Memory](https://appshunter.io/ios/app/card2memory/id1003066716) - [EqualizeMusic](https://appshunter.io/ios/app/equalizemusic/id6503642121) All apps by Karl-Heinz Loch: https://appshunter.io/developer/909594001 --- *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 2026-06-01.*