Buttons of Friends

All of these are endorsements

Fun Buttons

Some of these are endorsements

Random Links

None of these are endorsements

Electronics stuff:

https://smd.yooneed.one/
SMD Marking Database
https://learnemc.com/not-so-good-emc-design-guidelines
Info on emc and high-speed design (have not checked out the rest of the website)

Programming Things:

https://rosettacode.org/wiki/MD5/Implementation_Debug
Helpful to verify the inner workings on an MD5 Implementation (Why would you ever do that to yourself though)

Misc:

http://www.sparkbangbuzz.com/
Random Electronics and Chemistry Projects (Old and no TLS)