Симуляторы, soft, программы, tools

Easyeda https://www.youtube.com/watch?v=FCgx5-Aobss

Multisim https://www.ni.com/en/support/downloads/software-products/download.multisim.html#452133

Proteus 

Altium

SPICE LTSpice https://www.youtube.com/watch?v=5liB9th1clc

microcap

https://www.falstad.com/circuit/

deeptrace

solidworks

rfsim99 

https://www.youtube.com/watch?v=aQKJVfTI31I

https://www.youtube.com/watch?v=kv4cwBWwc90

sdr uno https://www.youtube.com/watch?v=aQKJVfTI31I

sdr spectrum analyzer https://youtu.be/aQKJVfTI31I?t=725

sdrplay rsp device controller

https://www.youtube.com/watch?v=plOQjJ38k3c

RF calcs 

http://www.tonnesoftware.com/

RFSim99_standalone

https://www.rtl-sdr.com/rfsim99-for-modern-windows-versions-free-rf-simulation-tool/

pcb layout

WOKWI - https://wokwi.com/projects/3531055619

Email:

Twillio, SendGrid

temp-mail.org

Diagrams:

app.diagrams.net sketchboard.me