Examine source code of Coupon Clipper

{
  "manifest_version": 2,
  "name": "Coupon Clipper",
  "version": "1.1.0",
  "description": "Clips the first 250 coupons at King Soopers, Kroger, or Sprouts with one click.",
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "browser_action": {
    "default_title": "Clip Coupons",
    "default_icon": {
      "48": "icons/coupon_clipper_icon_48.png",
      "96": "icons/coupon_clipper_icon_96.png"
    },
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.kingsoopers.com/*",
        "*://*.kroger.com/*",
        "*://*.sprouts.com/*"
      ],
      "js": [
        "content-script.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko_android": {},
    "gecko": {
      "id": "{45d795c9-3cf6-43ff-b75d-4f52ff721da4}"
    }
  }
}