Examine source code of My Different Extendsion

{
  "manifest_version": 2,
  "name": "My Different Extension",
  "version": "1.0",
  "description": "A different simple Firefox extension that shows an alert when loaded.",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [],
  "browser_action": {
    "default_title": "Different Extension"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b35b357b-2ec2-4787-8322-81f2bb07fcf2}"
    }
  }
}