Examine the display performance of page
$ git clone git@github.com:zaru/nakaguri.git
$ cd nakaguri
$ npm install
$ node app.js
http://example.com:3000/?url=http://example.com
# Smartphone UserAgent
http://example.com:3000/?url=http://example.com&ua=sp
# Callback mode (asynchronous)
http://example.com:3000/?url=http://example.com&callback=http://callback.example.com/