Examine source code of Email Current Tab

{
  "manifest_version": 2,
  "name": "Email Current Tab",
  "version": "1.1",
  "description": "Email the current tab's URL and content via Gmail",
  "author": "Yuval Pecht",
  "browser_specific_settings": {
    "gecko": {
      "id": "email-tab@yourdomain.com",
      "strict_min_version": "58.0"
    }
  },
  "permissions": [
    "activeTab",
    "storage",
    "tabs"
  ],
  "browser_action": {
    "default_icon": {
      "48": "icon48.png",
      "96": "icon96.png"
    },
    "default_popup": "popup.html",
    "default_title": "Email Current Tab"
  },
  "options_ui": {
    "page": "options.html"
  },
  "icons": {
    "48": "icon48.png",
    "96": "icon96.png"
  }
}