Examine source code of Minionize

{
  "manifest_version": 2,
  "name": "Minions",
  "version": "1.2resigned1",
  "description": "Replace a page with a minion from Despicable Me by right clicking the page and clicking 'Minionize'",
  "icons": {
    "48": "images/minioneye.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "css": [
        "styles/index.css"
      ]
    }
  ],
  "permissions": [
    "activeTab",
    "contextMenus"
  ],
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{321e8405-3f74-4b6d-accc-5e2607e35000}"
    }
  }
}