Examine source code of Better Eye

{
  "manifest_version": 2,
  "name": "__MSG_appName__",
  "version": "1.2.0",
  "description": "__MSG_appDesc__",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "icons": {
    "128": "main128.png"
  },
  "default_locale": "en",
  "browser_action": {
    "default_popup": "index.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e5022060-b8f1-41de-9241-5d474f4d8d4e}"
    }
  }
}