Editor Latex Online - Overleaf

 https://pt.overleaf.com/

Test Regex Online

 https://regex101.com/

Open an Online Development Enviroment in a container with the git repository code

https://www.gitpod.io/


Open your browser with addres like this

gitpod.io/#type_here_the_git(hub/lab/bitbucket)url

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https://codeanywhere.com/

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https://azure.microsoft.com/pt-br/services/visual-studio-online/
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https://codesandbox.io/
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https://online.visualstudio.com/
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https://analyticsindiamag.com/top-8-alternatives-of-github-codespaces/
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github1s

for example to access this repo inside Visual Studio Editor
https://github.com/Spiderpig86/Cirrus.
replace github.com by github1s.com
https://github1s.com/Spiderpig86/Cirrus.

For arduino 

https://codebender.cc/

Draw diagrams online for free

Draw.io online

 https://app.diagrams.net/

Convert PNG Images into the formats required for my UTFT libraries for Arduino

 http://rinkydinkelectronics.com/t_imageconverter565.php

Online Clipboard

 

Sprunge Form

Floating Point Converter Online

 https://www.h-schmidt.net/FloatConverter/IEEE754.html

https://www.binaryconvert.com/convert_float.html

Listen the world - Websites to listen to radio around the world with a diferent interface

Watch a video from a car riding in the city you choose and listen to a local radio
https://driveandlisten.herokuapp.com/

Point to  a place  in the Globe similar to Google Earth, and listen to the radio of that place
http://radio.garden/

2 Excellent online tools to use as Electronics Simulator

https://www.multisim.com/create/


https://www.tinkercad.com/dashboard?type=circuits&collection=designs