Examine source code of Shelvable

{
  "manifest_version": 2,
  "name": "Shelvable",
  "description": "Keep your reading lists just a click away.",
  "version": "1.1resigned1",
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "activeTab",
    "contextMenus"
  ],
  "icons": {
    "16": "icon-16.png",
    "48": "icon-48.png",
    "128": "icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{39c581e1-88f7-4b98-b258-4c9e692911fc}"
    }
  }
}