Examine source code of IMEI Generator

{
  "manifest_version": 2,
  "name": "IMEI Generator",
  "version": "0.0.0.2",
  "description": "It generates IMEI codes with right-click context menu or by clicking on its button.",
  "homepage_url": "https://github.com/Eraz1997/imei-generator",
  "icons": {
    "12": "icons/icon-12.png",
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "64": "icons/icon-64.png",
    "128": "icons/icon-128.png",
    "256": "icons/icon-256.png",
    "512": "icons/icon-512.png"
  },
  "permissions": [
    "activeTab",
    "contextMenus",
    "menus"
  ],
  "browser_action": {
    "default_icon": {
      "12": "icons/icon-12.png",
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "64": "icons/icon-64.png",
      "128": "icons/icon-128.png",
      "256": "icons/icon-256.png",
      "512": "icons/icon-512.png"
    },
    "default_title": "IMEI Generator",
    "default_popup": "popup/imei-popup.html"
  },
  "web_accessible_resources": [
    "beasts/frog.jpg",
    "beasts/turtle.jpg",
    "beasts/snake.jpg"
  ],
  "background": {
    "scripts": [
      "./scripts/imeiGenerator.js",
      "./scripts/background.js"
    ]
  }
}