Examine source code of Year Progress

{
  "name": "__MSG_appName__",
  "description": "__MSG_appDescription__",
  "version": "2.1.2",
  "short_name": "__MSG_appShortName__",
  "manifest_version": 2,
  "default_locale": "en",
  "icons": {
    "16": "images/icon-16.png",
    "128": "images/icon-128.png"
  },
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  },
  "minimum_chrome_version": "10.0",
  "chrome_url_overrides": {
    "newtab": "pages/newtab.html"
  },
  "omnibox": {
    "keyword": "year-progress"
  },
  "permissions": []
}