Electronic Toolbox Pro 4+

Electronics Engineering

Marcus Roskosch

    • 4.7 • 225 Ratings
    • $6.99



The *** ORIGINAL *** Electronic Toolbox Pro App
"The best and most complete Electronics App on the App Store" for Professionals, Hobbyists, Makers, HAMs and Students right at your fingertips!

Best of all: Continuously improved since 2009 - FOR FREE - NO IN APP PURCHASE - NO FAKE REVIEWS!

What users wrote about this app:

Well worth the money *****
I researched all EE apps before buying this one and I have to say that this one is the best by far. The developer is very accommodating to requests and suggestions and provides updates frequently. Very, very happy with this app.

Simply brilliant *****
I don't normally review apps but I was so impressed with this one I felt I had to make a brief comment. Buy it, I promise you won't be disappointed.

Supports iOS 14 back to iOS 11 and all available Apple iPhone and iPad models.

See the online Manual at http://go-to.me/etb-manual

Feature Highlights:
■ Circuit Editor
■ Most comprehensive and complete Electronics app available
■ Designed for Novices as well as Experts
■ Numerous individual tools from "A" like ASCII Table to "Z" like Zener Diode calculation. If something is missing, just let me know
■ Provides wide variety of simple and complex tools, such as the resistor color code conversion to the PCB Trace width tools
■ Various calculation tools available, such as the NE555 circuit calculation and the passive cooling calculator
■ Includes reference tools with millions of component specs for ICs, Transistors, FETs, Controllers with parametric searches, pinout and cross reference information, and complete datasheets
■ Provides information about Batteries, Drill sizes, Hybrid Amplifiers, Socket pinouts, package sizes and much more
■ Includes conversion tools, such as the Unit conversion tool, the HEX/Decimal/Float Tool, Frequency and AWG / SWG tools
■ Parametric search for Components with certain specs and cross references
■ Global search for terms or components across all tools
■ Customizable arrangement of tools for quick and easy access
■ Includes a scientific desktop calculator, a frequency generator, and an oscilloscope
■ Comprehensive reference glossary (english only)
■ Content can be updated "over-the-air" and amended quickly and easily
■ Store diagrams, documents, and specs of a project
■ iCloud support
■ No ads or in-app purchases
■ Can be used without Internet access
■ Special keyboard available for quicker entry of SI units
■ And much more...

Now also includes reference tools for major boards like RaspBerry Pi, Arduino, BeagleBone, TI-Launchpad, Nano Pi, Orange Pi, Banana Pi, Odroid, Cubieboard and SparkFun!

For further information about this App, just have a look at my website: ■ electronic-toolbox.com ■ or just send me an E-mail.

The new Version of the app has just been released and as always, this update is FOR FREE to all users of Electronic Toolbox.

At this point, many thanks for the ideas and suggestions I have received from the huge user community. You helped me to keep on improving my app with every new update.

This App will continue to live and grow over the time. So I still look forward to all additional ideas, suggestions or even criticism so that I can continuously improve my App.

Best regards,


Read more on : http://go-to.me/etb

What’s New

Version 14.5.01

This update includes the following changes and fixes:

◉ Further improvements for a next iOS Version

◉ Some bug fixes and improvements

◉ Several changes under the hood

Thanks for your great support and feedback which helps to further improve this App.

Please use the Contact Developer feature inside the App to contact me in case of questions or issues.

Stay safe and healthy!

Best regards,


Ratings and Reviews

4.7 out of 5
225 Ratings

225 Ratings


Convenient Practical for Hobbyists AND Engineers

Marcus has developed a great iPhone app for electronic hobbyists and engineers to have handy in your pocket. It provides handy reference to pinouts, specs, component markings, formulas, calculators, electronic related physics reference, on and on, in an easy to navigate and use format.
I use it to explore microcomputer chips, both pic and atmel, when beginning a project away from my computer and with a little time to kill while waiting for whatever.
Even when at my computer, it is great to look up this and that without having to radio-button back and forth between so many windows, or having to print something out just to refer to while I'm working.
Marcus has been updating and expanding this app for years now, and doesn't keep hitting his customers up to pay and pay for updates like some developers do, nor does he abandon the app when iOS requires compatibility updates.
If you are an active hobbyist or a napkin-doodling engineer, you will not regret purchasing this app!

Fulton K. Grimm ,

Reference goldmine

Engineering reference materials is a classic app domain for pocket oracles, and some of them have become quite polished in very focussed topic areas. What makes this app so valuable to me is that I need not remember which one of several apps holds the golden ticket for the task at hand. The cherry on top is that said convenience doesn’t require diluting expectations as to coverage or sophistication. The only advice is that time spent perusing the embarrassment of riches will be well rewarded, and there is always something else to be explored. I don’t know an engineer who would consider this a bug, but rather a feature.

D39692828 ,

An impressive reference

Wow! I was absolutely blown away by the sheer amount of content in this app. I discovered this when I was using a competing app that I found very lacking, especially in the area of microcontrollers. I decided to take a chance on this one and was just blown away by how much more content was in this one.

I would love to see more microcontroller/SBC content added, like more boards and pinout diagrams for the existing library. Seeing the frequency of updates, I’m hoping that will continue to evolve and I’ll be submitting some more feature requests. Super impressed, keep up the good work!

App Privacy

The developer, Marcus Roskosch, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

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