Examine source code of Foxy Credit

{
  "manifest_version": 2,
  "name": "FoxyCredit",
  "version": "3.0",
  "description": "Adds browser action icon to toolbar to open foxycredit.com startingpage",
  "homepage_url": "https://foxycredit.com/",
  "icons": {
    "48": "icons/icon48.png"
  },
  "browser_action": {
    "default_icon": "icons/icon32.png",
    "default_title": "FoxyCredit"
  },
  "permissions": [
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}