Examine source code of trackr.sh

{
  "manifest_version": 2,
  "name": "trackr.sh",
  "version": "1.1",
  "description": "Integrates trackr.sh in Mozilla Firefox",
  "homepage_url": "https://trackr.sh",
  "icons": {
    "48": "icons/trackr-48.png",
    "96": "icons/trackr-96.png"
  },
  "permissions": [
    "contextMenus",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background-script.js"
    ]
  }
}