Examine source code of ffCK Iframes

{
  "manifest_version": 2,
  "name": "ffCK Iframes",
  "description": "Removes the first iframe from the page. Forked from the firefox ffckoverlay extension.",
  "version": "1.0.0",
  "homepage_url": "https://github.com/mrwm/ffckiframes",
  "icons": {
    "48": "icons/ext-48.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "activeTab",
    "menus"
  ]
}