DesignSpark PCB - Printed Circuitboard Design
DesignSpark PCB is only one of the very useful applications developed by RS Components. It takes care of all your circuitboard design requirements.
Although DS PCB is free to use, you will have to register your copy online first.
TinkerCAD - Online 3D Design Software
Tinkercad is a free online 3D design and printing app. It is effective for smaller designs and projects.
As Tinkercad is free, it is a popular tool used by designers and hobbyists to make tools, models and prototypes.
SD Card Formatter - Raspberry PI SD Card Tool
SD Association offers this free tool for formatting SD cards. It is easy to use and automatically detects the SD card capacity.
This tools does not support Windows "BitLocker To Go", but its simplicity is good for using it with a Raspberry PI.
Win32 Disk Imager - Raspberry PI SD Card Tool
Free tool for writing images to SD cards. Linux images (bin files) can easily be saved to the SD card you would like to use with your Raspberry PI.
It is also simple to use the same tool for making backups of your Raspberry PI OS.
NodeMCU Flasher - Espressif EEPROM Flashing Tool
A free tool developed by NodeMCU for the flashing of their LUA development boards.
If you have a USB to TTL converter (programming cable), you can also use this tool to flash the native Espressif ESP8266 microcontrollers.
Arduino IDE - Arduino Programming Tool
An open-source IDE that makes it easy to write code and upload it to Arduino boards. It is scalable and supports a variety of different hardware platforms (like the ESP controllers), thanks to a very active community.
It runs on Windows, Mac OS X, and Linux.
Visual Studio Community - Microsoft Suite
Microsoft's flagship development environment features a fully-featured, extensible, free IDE for creating modern applications (Android, iOS, Windows), as well as web applications and cloud services.
Through the Visual Micro plug-in, this IDE can program a variety of microcontrollers.
Visual Micro - Visual Studio Arduino Plug-in
Visual Micro is a C++ plugin for Microsoft Visual Studio or AVR Studio for the creation of Arduino compatible cross-platform programs.
The free version of Visual Micro is limited though and not available for commercial use. All licenses are sold per computer.
AVR Studio - Atmel Development Suite
A free IDE for developing and debugging Atmel microcontroller (MCU) applications written in C, C++ or assembly. It also connects seamlessly to Atmel debuggers and development kits.
Through the Visual Micro plug-in, this IDE can program a variety of microcontrollers.
Atom IDE - Stand-alone Editor and Programming Tool
Atom is an open-source, highly customizable, cross-platform text editor. Like the major players (Visual Studio, AVR Studio), it also features code completion.
There is quite a large community for Atom, with plug-ins and packages being released frequently.
EveryCircuit - Circuit Simulation Software
Paid app that can build and simulate circuits on your phone or tablet. Current and voltage thresholds can be safely tested without the fear of burning up LED's or other components. The app also allows you to access the online community where there are thousands of examples available for download, as well as support from fellow enthusiasts on any questions you might have.
Electronic Toolbox - Reference and Calculation app
Paid app that provides you with an exhaustive list of electronic reference material, as well as calculation and conversion tools. Whether you need to calculate the resistance over a blue LED, or the required thickness of a track on a circuit board, this app will give you a collection of the most important electrical information at a time when you need it.
