Examine source code of Browser Song Recorder

{
  "manifest_version": 2,
  "name": "Browser Song Recorder",
  "version": "1.0",
  "description": "Record audio played in the browser (choose a tab/window) and export the recording (WAV).",
  "icons": {},
  "browser_action": {
    "default_title": "Browser Song Recorder",
    "default_popup": "popup.html"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{bce575e0-84ce-4083-a4e9-fc18d6db73e3}"
    }
  }
}