Examine source code of Fantrax Game Cap Tracker

{
  "manifest_version": 2,
  "name": "Fantrax Game Cap Tracker",
  "version": "1.2",
  "icons": {
    "16": "images/basketball_16.png",
    "48": "images/basketball_48.png",
    "128": "images/basketball_128.png"
  },
  "permissions": [
    "activeTab",
    "scripting",
    "webNavigation",
    "https://www.fantrax.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "images/basketball_16.png",
      "48": "images/basketball_48.png",
      "128": "images/basketball_128.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6d7359c9-cfe8-4151-8e14-5163d38ef9e9}"
    }
  }
}