Examine source code of Emoji Box

{
  "name": "Emoji Box",
  "version": "1.4.91.1636",
  "manifest_version": 2,
  "description": "Can be used to enter emojis, open from menu of the input box.",
  "author": "Yulon",
  "icons": {
    "16": "16.png",
    "48": "48.png",
    "128": "128.png"
  },
  "permissions": [
    "activeTab",
    "contextMenus"
  ],
  "background": {
    "scripts": [
      "bext.js",
      "bg.js"
    ]
  }
}