Examine source code of MyJs

{
  "manifest_version": 2,
  "name": "MyJs",
  "version": "1.3",
  "default_locale": "en",
  "description": "Add my JavaScript to the web page",
  "icons": {},
  "browser_action": {
    "default_icon": {},
    "default_title": "My Js",
    "default_popup": "pop.html",
    "chrome_style": true,
    "browser_style": true
  },
  "options_ui": {
    "page": "pop.html",
    "open_in_tab": true,
    "chrome_style": true,
    "browser_style": true
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "activeTab",
    "menus",
    "contextMenus",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "myjs@id"
    }
  }
}