Platform icons: Font Awesome Free 6.7.2, by Fonticons, Inc.
Android and Apple icons are unmodified SVG artwork from the original project.
Icons licensed under Creative Commons Attribution 4.0 International (CC BY 4.0).
https://fontawesome.com/license/free
https://creativecommons.org/licenses/by/4.0/
Sources:
https://github.com/FortAwesome/Font-Awesome/tree/6.7.2/svgs/brands
Android and Apple names/logos identify their respective platforms.