Design resources
Install sketchtool
$ brew install brew-cask
$ cask install sketch-tool
Use gulp to publish images under ./sketch/out
$ npm install
$ gulp
$ tree ./sketch
./sketch
├── out
│ ├── houkago-icon-candidate1.png
│ ├── houkago-icon-candidate2.png
│ └── houkago-icon-candidate3.png
└── source
└── houkago-icon.sketch