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Electronic Toolbox Pro - Elektronics and electrical engineering for engineers, students and hobbyists

By Marcus Roskosch

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The ORIGINAL Electronic Toolbox Pro App
Electronic reference and calculation resource for Professionals, Hobbyists, 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 accomodating 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 9 back to iOS 7 and all Apple devices from iPod Touch, all iPhone and iPad models including 6s+ and iPad pro

Feature Highlights:
■ 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
■ Paremetric 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 and Dropbox 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...

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

Version 9 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,


What's New in Version 9.01.01

New Data Update December 13. 2015:

A new Data Update 9.02 is available with the following changes:

- Additional Coax Types (Belden)
- Mini-DIN Sockets added
- HAM Radio RIG Socket Pinouts
- Aviation Pinouts
- Additional data and information for the packages tool
- The Tubes had lost their Pinout images for some reason. They are now back, sorry.
Quite a few amendments and corrections for the existing databases

The new App Update 9.01.01 contains the following changes:

This version contains new tools, many feature improvements and of course some bug fixes.

New tools:

■ Optocoupler Database – This new Database tool contains more than 400 Optocoupler types including description and pinout
■ Packages Database – This new tool contains more than 300 Package types like DIP, DIP, TO, SIP, SOT etc.

The following new features have been implemented:

■ iOS 9

Electronic Toolbox and RF-Toolbox are now not only fully compatible with iOS 9 (while still backward compatible down to iOS 7), they also support new features introduced with iOS 9 such as:

■ Split view (use the App side by side with another App)
■ Multitasking (App will continue to run in Split view)
■ Improved user interface on iPhone 6 plus and 6s plus in landscape mode

Additional improvements:

■ Now it is possible to directly jump to the compatible types listed inside the transistors, FETs etc.
■ You can now also directly jump to the 74xx and 40xx ICs from inside the Logic tool
■ The Battery charge tool can now also calculate discharge
■ Improved Database parametric filtering
■ Substrate Dielectric can now be selected (e.g. FRA4, GETEC, Polyimide etc.) in the PCB tools (RF-Toolbox only)
■ The voltage divider now also displays ratio between R1/R2 and V1/V2
■ Generator, Scope and Frequency counter now allows input and output either on built in speaker / microphone or headphone plug
■ Upon request, the Frequency tool can now again convert between Period/Frequency/Wavelength
■ Tools like the Raspi tool now have “Useful links“
■ The PV 4-20mA tool now shows sample values in 10% steps (linear and square root)

Improvements in the Projects section:

■ Many additional components added
■ The component browser now allows to search for component types
■ Inside the project, you can now directly jump to the corresponding tool for a certain component. This way, you can now easily double check the pinouts, datasheets or color-code directly from inside the project tool

Bug fixes:

■ The Battery plot function is now working again
■ Some corrections in the parametric filters
■ Some corrections in the calculation of the Toroid tool
■ Some general corrections in the transformer tool
■ Three ring m Ohm values are now accepted in the Resistors tool

Please note, as mentioned in my blog on, there will soon be some additional updates. If you experience some issues or have additional requests or ideas, please let me know quickly so I can consider this for the next update.

Thank you all for your great support!

Please don't forget to rate this App.

Thank you,

Best regards,



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Customer Reviews

Outstanding app

The variety of tools and depth of information make this an excellent addition to the hobbyist's toolkit. I wish it were possible to add my own entries into the database (e.g. pinouts for 65C22, various CPLDs, etc.) but that's a quibble, given how much data and useful functionality this app contains.

Marcus' support for the toolbox is superior--updates come at reasonable intervals and always increase the usefulness of the app.

Truly an outstanding value.

Excellent app, comprehensive, well supported

This app gets as much use on my workbench as my multimeter or oscilloscope - it's become an essential tool. A huge number of references and calculations needed while bread boarding and testing circuits are here, sensibly organized, and easy to use.

Support is very responsive, and the app is constantly getting new features and better performance. Thank you Marcus!

Great EE app for hobbyists and pros

By far the best app for electronics reference. I use it constantly to pull up cmos and ttl IC pin outs - sure beats flipping through the cookbooks. Plus great developer support. And it allows you to customize which topics appear, so can take out PCB trace info, etc. if you don't need it.

Electronic Toolbox Pro - Elektronics and electrical engineering for engineers, students and hobbyists
View In iTunes
This app is designed for both iPhone and iPad
  • $5.99
  • Category: Productivity
  • Updated:
  • Version: 9.01.01
  • Size: 83.6 MB
  • Languages: English, French, German, Italian, Russian, Simplified Chinese, Spanish, Traditional Chinese
  • Seller:

Compatibility: Requires iOS 6.1 or later. Compatible with iPhone, iPad, and iPod touch.

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