Examine source code of HelloSurf

{
  "name": "HelloSurf",
  "version": "1.0",
  "description": "Check the surfing conditions right from your browser",
  "manifest_version": 2,
  "icons": {
    "48": "surfing_Indo.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Check the SURF here!"
  }
}