Examine source code of Live CSS Editor

{
  "manifest_version": 2,
  "name": "Live CSS Editor",
  "version": "1.0",
  "description": "Edit CSS styles live on any webpage.",
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "icons": {
    "48": "icon.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{064f58fe-f486-4907-a156-ce2b5e755add}"
    }
  }
}