国外非常全的免费图标库，种类丰富
Icon Font, SVG, PDF & PNG Generator
4,425,000+ free and premium vector icons in SVG, PNG, CSH and AI format
The premium icon font for Ionic Framework
Search 590,912 free icons
PNG、ICO、ICNS格式图标搜索、图标下载服务
2,100,000+ free and premium vector icons.
