Examine source code of TwitMarks

{
  "name": "TwitMarks",
  "version": "0.0.3resigned1",
  "manifest_version": 2,
  "description": "Add Twitter Bookmarks to web",
  "homepage_url": "https://geekodour.github.com",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "default_locale": "en",
  "background": {
    "page": "src/bg/background.html"
  },
  "page_action": {
    "default_icon": "icons/icon19.png",
    "default_title": "page action demo",
    "default_popup": "src/page_action/page_action.html"
  },
  "permissions": [
    "tabs",
    "activeTab",
    "webRequest",
    "cookies",
    "https://*/*",
    "http://*/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://*.twitter.com/*"
      ],
      "css": [
        "src/inject/inject.css"
      ],
      "js": [
        "src/inject/inject.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{b9f175a2-9bfe-407e-af5b-e094ba6a545e}"
    }
  }
}