Look at that! Flat icons escaped to a new dimension.
A ton of cool material design icons.
Buy Set of Thin Line Flat Design Icons of Business Essentials by PureSolution on GraphicRiver. Set of modern thin line icons of basic business essential tools, office equipment, communication, online support, soc.
Icons pack by Hakan Ertan, via Behance
This set contains 60 free flat icons which are designed in both round and flat style. These free flat icons come in PNG, SVG, EPS, PSD, AI format.