Examine source code of Web Tools Launcher

{
  "manifest_version": 2,
  "name": "Web Tools Launcher",
  "version": "1.0",
  "description": "Launch your favorite set of web tools with a single click.",
  "permissions": [
    "tabs"
  ],
  "browser_action": {
    "default_icon": "icons/launcher-48.png",
    "default_popup": "popup.html",
    "default_title": "Web Tools Launcher"
  },
  "icons": {
    "48": "icons/launcher-48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{13a3e31e-9dfe-40c6-be7a-e02fe288a7eb}"
    }
  }
}