Examine source code of Expense Tracker Basic

{
  "manifest_version": 2,
  "name": "Expense Tracker Basic",
  "version": "1.0",
  "description": "Expense Tracker is a useful utility that allows you to enter an amount, a name, and a filter that will calculate the total",
  "permissions": [],
  "browser_action": {
    "default_popup": "game.html",
    "default_icon": {
      "128": "images/tracker-logo.png"
    }
  },
  "icons": {
    "128": "images/tracker-logo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ea399247-e9cd-4a35-a2d9-d916eb5abdb0}"
    }
  }
}