AddThis - AddThis free website tools include share buttons, targeting tools and content recommendations help you get more likes, shares and followers and keep them coming back.
ShareThis - Grow your audience with easy-to-use sharing tools.
AddToAny - Share buttons by AddToAny, the universal sharing platform for websites and apps.
Font Awesome - Font Awesome makes it easy to add vector icons and social logos to your website. And version 5 is redesigned and built from the ground up!