Making the icons for front-end developers
We create the icons based on the guidelines of the OS makers:
We release bunch of icons under our Good Boy License: color, Windows 10, WPF, and new iOS 11 glyphs. We've also assembled the popular open source icons packs with our (otherwise paid) tools. We have the icon-sized logos also for free.
And, finally, we have open sourced the bunch of our code, include an HTML pre-generator for Googlebot.