Nucleo is a beautiful library of 25K icons, and a powerful application to collect, customize and export all your icons.
The icon editor is a simple, yet powerful tool that lets you recolor, edit and tweak icons easily. All vector icons on Iconfinder have a new Edit icon button that opens the icon in the editor. It's also possible to use the editor for icons from your hard drive. Once you are done editing, it's easy to export into SVG or PNG.