Examine source code of Kitten Block

{
  "manifest_version": 2,
  "name": "Kitten Block",
  "description": "Replaces the Daily Mail and Express with Tea and Kittens",
  "version": "2.0.2resigned1",
  "applications": {
    "gecko": {
      "id": "kittenblock@tomroyal.com"
    }
  },
  "permissions": [
    "tabs"
  ],
  "icons": {
    "32": "icon.png"
  },
  "background": {
    "scripts": [
      "kittenblock.js"
    ]
  }
}