Examine source code of Volume Booster

{
  "browser_specific_settings": {
    "gecko": {
      "id": "{129c5659-65fd-4f79-8560-17413cde9bb9}"
    }
  },
  "description": "Boost page volume past 100 percent. Raise quiet videos, fix low site audio, and pan, mono, or flip left and right channels.",
  "icons": {
    "48": "icon.svg",
    "96": "icon.svg"
  },
  "name": "Sound Control",
  "version": "4.7.1",
  "manifest_version": 2,
  "browser_action": {
    "default_icon": "icon.svg",
    "theme_icons": [
      {
        "dark": "icon.svg",
        "light": "icon-inv.svg",
        "size": 64
      },
      {
        "dark": "icon.svg",
        "light": "icon-inv.svg",
        "size": 48
      },
      {
        "dark": "icon.svg",
        "light": "icon-inv.svg",
        "size": 32
      },
      {
        "dark": "icon.svg",
        "light": "icon-inv.svg",
        "size": 16
      }
    ],
    "default_popup": "popup.html",
    "default_title": "SoundFixer",
    "browser_style": true
  },
  "permissions": [
    "activeTab",
    "webNavigation",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ]
}