nounproject: Calmcode has gotten many compliments over the years because of it's icons. The truth is that we don't deserve any of the credit for them though; they are all from the nounproject.
It started as a kickstarter project back in 2011 and has been going strong ever since. It's a service that is able to retreive icons for just about any noun out there. You can use the icons for free if you attribute the artist, but you can also use their paid service instead for a few dollars a month.
The upgrade comes with a lovely desktop app that allows you to search, then click-and-drag icons into the app that you're working with. You're able to copy SVG images or PNGs, which means that both VSCode or Keynote can just accept them right away.
It's a great service, really (!), we can recommend it to many folks!