Examine source code of Leads Tracker

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Leads Tracker",
  "description": "Helps you to keep a track of your important leads. Ideal for Sales and Businesses.",
  "icons": {
    "128": "128.png",
    "512": "logo.png"
  },
  "action": {
    "default_popup": "chrome_extension.html",
    "default_icon": "128.png"
  },
  "permissions": [
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{401f3512-a429-4574-8e69-5d260f9f55aa}"
    }
  }
}