Examine source code of Blood Pressure Tracker

{
  "manifest_version": 2,
  "name": "Blood Pressure Tracker",
  "version": "1.0",
  "description": "Track and save your daily blood pressure readings.",
  "permissions": [],
  "browser_action": {
    "default_popup": "index.html",
    "default_icon": {
      "128": "images/blood-logo.png"
    }
  },
  "icons": {
    "128": "images/blood-logo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4ef1298a-6adf-455e-b03b-7ea2ec1226c7}"
    }
  }
}