Examine source code of 17TRACK

{
  "manifest_version": 2,
  "name": "17TRACK",
  "version": "1.0.1",
  "description": "All-in-one Package Tracking Extension!",
  "icons": {
    "16": "img/icon_16x16.png",
    "48": "img/icon_48x48.png",
    "128": "img/icon_128x128.png"
  },
  "background": {
    "scripts": [
      "js/utils.min.js",
      "js/background.min.js"
    ]
  },
  "browser_action": {
    "default_icon": "img/icon_48x48.png",
    "default_title": "17TRACK"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/utils.min.js",
        "js/content_scripts.min.js"
      ],
      "run_at": "document_end"
    }
  ],
  "permissions": [
    "contextMenus",
    "tabs",
    "http://*/*",
    "https://*/*"
  ],
  "web_accessible_resources": [
    "js/inject.min.js",
    "img/icon_48x48.png"
  ],
  "homepage_url": "https://extcall.17track.net/",
  "omnibox": {
    "keyword": "17TRACK"
  }
}