Examine source code of SoundSphere

{
  "manifest_version": 3,
  "name": "SoundSphere",
  "version": "1.3.0",
  "description": "Per-tab volume boost and 10-band EQ for browser audio.",
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon/speaker16px.png",
      "32": "icon/speaker32px.png",
      "48": "icon/speaker48px.png",
      "96": "icon/speaker96px.png",
      "128": "icon/speaker128px.png"
    }
  },
  "icons": {
    "16": "icon/speaker16px.png",
    "32": "icon/speaker32px.png",
    "48": "icon/speaker48px.png",
    "96": "icon/speaker96px.png",
    "128": "icon/speaker128px.png"
  },
  "background": {
    "scripts": [
      "background.firefox.js"
    ]
  },
  "permissions": [
    "activeTab",
    "storage",
    "tabs"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start",
      "all_frames": true,
      "match_about_blank": true
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "fonts/JetBrainsMono-ExtraBold.woff2",
        "inject/webaudio_tap.js"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "soundsphere@dzl",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  }
}