Design Mobile App Icons:
1. 学习Icon 设计的标准
Interface Guidelines:
Google Material Design: 中文版：http://design.1sters.com/material_design/style/icons.html
Apple Human Interface Guidelines: https://developer.apple.com/ios/human-interface-guidelines/overview/themes/
2. 应用Sketch 模板
Sketch新建文件里有用于 IOS icon/ Android Icon design的template, 设计第一个icon。
较老的sketch版本， 可以通过使用快捷键 “A” 打开模板， 在侧边栏里选择icon 的模板。
3. 使用Plugin: Aeiconizer 生成所需的其它尺寸的icon。
IOS icon generator plugin. This is a great little plugin for quickly being able to build out all of the app icons we'd need when building out mobile apps for Android and iOS. We can change the original design and go ahead and run it again and there's nota bunch of time trying to fix every single little app icon we created the first time around.
4 . 使用快捷键一次全部导出。
Icon Export: Command+Shift+E Export all artboard, and can select any of them.
