Examine source code of Wayback Machine Helper

{
  "manifest_version" : 2 ,
  "name" : "Wayback Machine Helper",
  "version" : "0.8resigned1",
  "description" : "Search and access the current URL on archive.org's Wayback Machine. Access it by raising the context-menu by right-clicking on a page, or a link.",
  "author": "gammy",
  "homepage_url" : "https://github.com/gammy/wayback_helper",
  "icons" : {
    "16" : "icons/wayback-16.png",
    "24" : "icons/wayback-24.png",
    "32" : "icons/wayback-32.png",
    "48" : "icons/wayback-48.png",
    "64" : "icons/wayback-64.png"
  },
  "background" : {
    "scripts" : [
      "wayback_helper.js" 
    ]
  },
  "permissions" : [
    "tabs" ,
    "contextMenus" 
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{fff3a8b2-f857-4b17-bd72-3350035cbd24}"
    }
  }
}