Examine source code of CouponLime

{
  "manifest_version": 2,
  "name": "CouponLime",
  "description": "CouponLime helps you save money with coupon codes at over 200,000+ stores.",
  "version": "1.0.2",
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "CouponLime"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "img/logo-16.png",
    "48": "img/logo-48.png",
    "128": "img/logo-128.png"
  },
  "permissions": [
    "tabs",
    "storage",
    "activeTab"
  ]
}